USDT, USDC and FDUSD Explained

By Tommy Tietze, CEO of ArrowTrade AG

Stablecoins are often treated as if they were simply “digital dollars”.

That is understandable, but it is too superficial. Anyone who trades actively, moves capital between exchanges or uses automated trading strategies does not use stablecoins only as a parking space. Stablecoins are liquidity tools, accounting units, fee levers, risk factors and sometimes the silent part of a trading setup that receives far too little attention.

Most investors look at Bitcoin, Ethereum or the next altcoin first. The stablecoin in the background feels boring because, ideally, it does not move much. That apparent boredom is exactly what makes it dangerous. If a stablecoin fails to do what it promises, the issue does not only affect one coin. It affects liquidity, execution, bookkeeping, tax records and, in extreme cases, trust in the broader market.

The European Central Bank describes stablecoins as digital units that aim to maintain a stable value relative to a currency or other assets, while also warning that stablecoins “may not be so stable after all” (European Central Bank).

This article explains the differences between USDT, USDC and FDUSD, why all three matter for crypto traders and what you should pay attention to when stablecoins are part of your setup.

What stablecoins are supposed to do

Stablecoins are designed to solve a problem that is visible in crypto every day: Bitcoin, Ethereum and many altcoins move heavily. Anyone who trades actively needs a unit in which profits, losses, cash positions and trading decisions become easier to measure.

A USD stablecoin aims to stay as close as possible to the value of one US dollar. USDT, USDC and FDUSD are examples of such stablecoins. They are often used as the quote currency in trading pairs, meaning they are the counter-currency against which Bitcoin, Ethereum or altcoins are bought and sold.

If you trade BTC/USDT, you buy or sell Bitcoin against USDT. If you trade ETH/USDC, you measure your Ethereum position against USDC. If you trade BTC/FDUSD, you use FDUSD as the accounting unit on Binance.

In everyday language, that sounds technical. In risk management, it matters a lot.

The stablecoin is not neutral.

It has an issuer, a reserve model, a regulatory profile, liquidity on specific exchanges and its own trust profile. Anyone who sees stablecoins only as “dollars on the blockchain” misses the points that matter most during market stress.

USDT, USDC and FDUSD

USDT is issued by Tether and is historically the largest and most liquid USD stablecoin in the crypto market. Its strength lies mainly in distribution, trading volume and acceptance across many exchanges and chains. For many traders, USDT is the default because the most liquid trading pairs often run against USDT.

USDC is issued by Circle and positions itself more strongly around transparency, compliance and reserve reporting. Circle describes USDC as fully backed by highly liquid cash and cash-equivalent assets and refers to monthly reserve attestations by a Big Four accounting firm (Circle).

FDUSD is different because it is especially relevant in the Binance ecosystem. Binance has supported selected FDUSD pairs through fee promotions in recent years, and according to Binance’s current announcement, zero maker fees remain in place for selected FDUSD spot and margin pairs, while standard taker fees have applied since January 29, 2026 (Binance Announcement).

All three stablecoins pursue the same basic goal: keeping their value as close as possible to the US dollar.

The difference lies in implementation, trust, transparency, liquidity, exchange integration and fee structures.

Why stablecoins matter

Stablecoins are more than a temporary step inside a trade.

They determine how you provide capital, how you move between positions and how you compare results. This becomes especially relevant in systematic or automated trading, because many strategies do not constantly move between euros and crypto. They operate inside the crypto ecosystem.

Example:

You hold capital in USDC and buy Bitcoin with it. When the trade closes, you are back in USDC. From the perspective of the trading system, USDC is the accounting unit. If USDC remains stable, that logic is simple. If the stablecoin comes under pressure, the supposedly neutral base becomes a risk factor itself.

With FDUSD, there is a second layer: fees.

If an exchange makes certain FDUSD pairs more attractive through maker-fee promotions, the economics of a strategy can change. That is especially relevant for systems that execute many small trades, because fees are not a side note when trade frequency is high.

This directly connects to position sizing. In the fourth article of this series, we covered why trade size often matters more than the entry.

type: embedded-entry-inline id: 2fFkuELu9dXrITnRoCYTUj

If you calculate your position size in stablecoins, you assume that the stablecoin unit remains stable, liquid and executable. If you also rely on a fee promotion, you need to know whether your strategy actually creates maker orders or whether it executes as a taker.

That is not a detail.

With many small trades, the difference between maker and taker execution can become visible over time.

USDT: liquidity first

USDT is deeply embedded in the crypto market.

Many exchanges, trading pairs and traders use USDT as the default. That network strength is a real advantage. Liquidity usually means better execution, tighter spreads and less slippage. For active traders, this is not a minor point.

If a trading pair is very liquid, larger orders can usually be executed more cleanly. If a pair is thin, even a smaller order can move the price or execute worse than expected.

This matters even more when automated strategies are used. A bot can place an order correctly from a technical perspective. Market liquidity still decides how well that order is executed.

The other side of the story is that USDT has faced repeated debate around transparency and reserve structure. Tether provides information about reserves and tokens issued on its transparency page (Tether).

For traders, this does not automatically mean that USDT is unsuitable. It means USDT should not only be viewed as a liquidity instrument. It also carries issuer and trust risk.

USDC: transparency first

USDC is often perceived as the more transparent stablecoin.

Circle publishes reserve information and describes USDC as redeemable 1:1 for US dollars and fully backed by highly liquid cash and cash-equivalent assets (Circle Transparency). Circle also states that most of the USDC reserve is held in the Circle Reserve Fund, an SEC-registered 2a-7 government money market fund managed by BlackRock (Circle).

That matters for many professional investors because they do not only want to know whether a stablecoin is liquid. They want to know how the reserve is structured, who manages it, how regularly reporting takes place and what legal framework stands behind it.

This makes USDC attractive for some setups, especially when transparency and regulatory alignment are weighted more heavily than maximum market liquidity.

USDC still carries risk.

In March 2023, USDC temporarily lost its peg after Circle disclosed that part of its cash reserves was held at Silicon Valley Bank during a period of banking stress (Circle).

Transparency reduces uncertainty.

It does not remove risk completely.

FDUSD: the Binance factor

FDUSD belongs in this discussion because stablecoins should not only be judged by reserve transparency or market size. For traders, the practical advantage on a specific exchange also matters.

On Binance, FDUSD is relevant for exactly that reason.

Binance has supported selected FDUSD pairs through zero-fee promotions. According to the current Binance announcement, standard taker fees have applied to selected FDUSD spot and margin pairs since January 29, 2026, while zero maker fees remain in place (Binance Announcement).

That sounds like a small distinction.

In practice, it is important.

Maker and taker

A maker order adds liquidity to the order book. This is usually a limit order that does not execute immediately and instead waits in the order book.

A taker order removes liquidity from the order book. This is usually a market order or a limit order that executes immediately against existing orders.

If Binance offers zero maker fees on selected FDUSD pairs, that can be attractive for strategies that work with calmer execution, limit orders and planned liquidity. If a strategy enters the market aggressively and executes as a taker, the fee logic is different, because Binance applies standard taker fees to selected FDUSD pairs under the current update (Binance Announcement).

This nuance matters.

FDUSD can be strong on Binance.

The advantage depends on the actual strategy, the trading pair and the execution logic.

Why this matters for automation

Automated trading is built on repetition.

One trade with small fees may not matter much. Many small trades across days, weeks or months change the equation. That is why fees are not an accounting detail. They are part of the strategy architecture.

If a bot trades frequently, maker-fee advantages on FDUSD pairs can matter. At the same time, this should never become a blanket rule. It depends on whether the system actually achieves maker execution, whether enough liquidity is available and whether the FDUSD pair fits the strategy.

For unCoded, this question is practical because the system focuses on automated Binance spot trading. If a strategy executes many small trades, quote currency, fee model, liquidity and order type need to be considered together.

Not every stablecoin fits every setup equally well.

And not every “zero fee” statement applies to every order type.

The real comparison

Many articles reduce stablecoins to simple statements.

USDT is more liquid. USDC is more transparent. FDUSD can be interesting on Binance because of fee mechanics.

That is useful as a starting point, but it is not a full decision framework.

USDT for liquidity

USDT often makes sense when market depth and broad availability matter most. Anyone trading across many exchanges and many pairs will usually encounter USDT everywhere.

USDC for transparency

USDC often makes sense when reserve disclosure, compliance and regulatory alignment matter more. Circle publishes reserve information and regular attestations (Circle Transparency).

FDUSD for Binance-specific fee logic

FDUSD can be attractive on Binance when relevant pairs are available and the strategy can benefit from zero maker fees. Binance lists BTC/FDUSD, BNB/FDUSD, DOGE/FDUSD, ETH/FDUSD, LINK/FDUSD, SOL/FDUSD and XRP/FDUSD among the selected FDUSD pairs in the context of the fee update (Binance Announcement).

The best stablecoin is not the best stablecoin in abstract terms.

The best stablecoin is the one that fits your exchange, strategy, liquidity needs, documentation process and risk profile.

Stablecoins and MiCA

In Europe, MiCA makes the stablecoin discussion more important.

The Markets in Crypto-Assets Regulation creates EU-wide rules for crypto-assets and includes asset-referenced tokens and e-money tokens. ESMA describes MiCA as a unified EU regulatory framework for crypto-assets and names transparency, disclosure, authorisation and supervision as central parts of the framework for issuers and service providers (ESMA).

The European Banking Authority states that issuers of asset-referenced tokens and e-money tokens must hold the relevant authorisation to carry out activities in the EU (European Banking Authority).

For investors in the DACH region, one question becomes more important:

Which stablecoins remain available on which platforms, under which conditions and with which regulatory structure?

This is not a detail for lawyers. It affects trading pairs, liquidity and product availability. If exchanges restrict or treat certain stablecoins differently in Europe, trading setups can be affected directly.

The first article in this series covered crypto taxes in Germany in 2026.

type: embedded-entry-inline id: 2kA1pyMZJn94ImazMkpPbt

Regulation, fees and tax records belong together because they point to the same development: crypto is becoming more professional, more visible and more connected to existing financial and reporting systems. Anyone still operating in 2026 as if it were 2020 will eventually face operational friction.

Stablecoins are not bank accounts

A stablecoin can feel like cash.

That feeling can be misleading.

USDT, USDC or FDUSD on an exchange are not the same as euros in a bank account. You hold a crypto-asset on a specific platform, dependent on a specific issuer and moved through a technical infrastructure.

The second article in this series covered exchange hacks, API keys and custody risk.

type: embedded-entry-inline id: 3Rj7iDVXrRiBU8RLP5Lk3N

This connection is especially important with stablecoins. If your stablecoins sit on a centralized exchange, you do not only carry stablecoin risk. You also carry exchange risk. If you hold them in your own wallet, you reduce some exchange risk, but you take on private-key responsibility.

The European Central Bank warns that stablecoins can create financial stability risks through de-pegging, runs and links to traditional finance as the market grows (European Central Bank).

For an individual investor, the simpler version is this:

Stablecoins are useful.

They are not a risk-free parking space.

Stablecoins and automated trading

Stablecoins are especially relevant for automated spot trading because they often form the base from which trades are opened and closed. A system that executes many small trades needs a stable quote currency, clean data, enough liquidity in the relevant pair and a fee logic that matches its execution style.

For unCoded, this is practical because the system is built around Binance spot trading. The capital remains on the user’s Binance account, the API key does not require withdrawal permissions, and the trading takes place without futures leverage.

That reduces certain risks.

It does not replace the decision about which pairs, stablecoins and reserves make sense.

If a user relies on USDT, they often get broad liquidity. If a user relies on USDC, they may weight transparency more heavily. If a user relies on FDUSD, the maker-fee structure on Binance can be interesting as long as the strategy uses that kind of execution and the relevant pair has enough liquidity.

Good infrastructure gives the user control.

It does not remove the responsibility to understand the base assets.

Stablecoins and technical analysis

At first glance, stablecoins have little to do with technical analysis.

They still affect the market you are analyzing. If you use RSI, MACD or other indicators on BTC/USDT, you are not analyzing “Bitcoin alone”. You are analyzing Bitcoin against USDT. BTC/USDC or BTC/FDUSD may look very similar most of the time, but differences can appear during stress if a stablecoin comes under pressure or liquidity shifts.

The third article in this series covered RSI.

type: embedded-entry-inline id: 2fFkuELu9dXrITnRoCYTUj

Indicators measure price behavior. Price behavior always exists in a specific market. A BTC/USDT chart is not exactly the same market as a BTC/EUR, BTC/USDC or BTC/FDUSD chart, even if the differences seem small during normal market conditions.

For professional setups, this is not academic.

If strategy, backtesting, execution and reporting run on different pairs, deviations can appear. The more systematic your trading becomes, the less you should ignore those details.

What investors should watch

Reserve quality

A stablecoin is only as strong as the confidence in its reserve structure and redeemability. Circle points to highly liquid cash and cash-equivalent assets as well as monthly attestations for USDC (Circle Transparency). Tether publishes its own transparency information on reserves and token circulation for USDT (Tether).

The question is not only whether reserves exist. It also matters how liquid they are, how transparently they are reported and how robust they appear during stress.

Liquidity

For traders, liquidity often matters more than theoretical elegance. A stablecoin with strong transparency does not help much if the actual pair on your exchange is thin and execution quality is poor.

Fees

FDUSD shows why fees belong in the stablecoin decision. Binance has kept zero maker fees for selected FDUSD pairs, while standard taker fees have applied since January 29, 2026 (Binance Announcement).

This means a strategy must know whether it creates maker or taker execution.

Platform availability

Not every stablecoin is equally available on every exchange, chain or product. Regulation can change that over time.

Chain risk

USDT, USDC and FDUSD are not only token names. They can exist on different networks. Ethereum, BNB Smart Chain, Solana, Tron, Base and other chains have different fees, outage risks, wallet support and infrastructure.

Documentation

Every stablecoin swap, order and transfer can later matter for taxes, reporting or internal analysis. Anyone making many small movements needs clean exports.

Practical checklist

Before using a stablecoin

• What role should the stablecoin play?

• Is it for trading liquidity, reserve holding, transfers or fee optimization?

• Which exchange or chain will be used?

• Is there enough liquidity in the relevant trading pair?

• How transparent is the reserve structure?

• Which maker and taker fees apply right now?

• How easily can transactions be exported?

• Are there regulatory restrictions in Europe?

• Is the stablecoin held on an exchange or in self-custody?

For automated trading

• Which quote currency does the strategy use?

• Are the trading pairs liquid enough?

• Is slippage considered in the setup?

• Are maker and taker fees treated separately?

• Is the stablecoin reserve chosen deliberately?

• Is there a plan if a stablecoin comes under pressure?

• Are trades and stablecoin movements documented cleanly?

FAQ

What is the difference between USDT, USDC and FDUSD?

USDT is mainly known for high liquidity and broad use in crypto trading, USDC positions itself more strongly around transparency and reserve reporting, and FDUSD is especially relevant in the Binance ecosystem because selected FDUSD pairs can be attractive through fee promotions. Binance states that standard taker fees apply to selected FDUSD spot and margin pairs since January 29, 2026, while zero maker fees remain in place (Binance Announcement).

Is FDUSD free to trade on Binance?

Not across the board. According to Binance, zero maker fees remain for selected FDUSD spot and margin pairs, while standard taker fees have applied since January 29, 2026 (Binance Announcement).

When does FDUSD make sense for traders?

FDUSD can make sense when you trade relevant FDUSD pairs on Binance, your strategy uses maker orders and there is enough liquidity in the selected pair. The advantage depends on order type, pair, liquidity and the current fee structure.

Is USDT safer than USDC?

There is no universal answer. USDT often has deeper liquidity in many trading pairs, while USDC places more emphasis on reserve transparency and compliance. Investors should look at liquidity, reserve structure, platform risk and the specific use case.

Can a stablecoin lose its value?

Yes. Stablecoins can lose their peg if market participants lose confidence in redeemability or reserve quality. The European Central Bank identifies de-pegging and runs as key stablecoin risks (European Central Bank).

Why are stablecoins important for crypto trading?

Stablecoins often serve as quote currencies, reserve positions and accounting units in crypto trading. They influence liquidity, execution, position sizing, fees, reporting and tax documentation.

What role does MiCA play for stablecoins?

MiCA creates EU-wide rules for crypto-assets, including asset-referenced tokens and e-money tokens. ESMA identifies transparency, disclosure, authorisation and supervision as central parts of the MiCA framework (ESMA).

Conclusion

Stablecoins look simple because they promise price stability.

That is exactly why they deserve attention.

USDT, USDC and FDUSD are not interchangeable placeholders. USDT is difficult to ignore for many traders because of liquidity and availability. USDC is interesting for many investors because transparency and regulatory structure play a larger role. FDUSD is especially relevant on Binance because fee promotions and maker-fee structures can affect the economics of a strategy.

A serious crypto setup does not only analyze the next trade. The base currency in which you calculate, hold and automate is part of the strategy, just like entry, exit, position size and API security.

Serious Crypto begins with these details.

Not because they are spectacular. Because they matter when the market is under pressure.

Disclaimer: This article is not financial advice. Stablecoins, crypto trading and automated trading strategies involve risk. Past stability, liquidity, fee promotions or market acceptance are no guarantee of future safety. Fee models and promotions can change and should be checked directly with the relevant exchange before trading.

More about automated crypto spot trading: uncoded.ch

More about ArrowTrade AG: arrowtrade.ch