Paying for every transaction
The first role is unavoidable, and it is the one people meet before any other. Every interaction with any application on BNB Smart Chain is a transaction, and every transaction costs a fee paid in BNB, so a wallet holding a substantial balance of anything else and no BNB cannot do anything at all.
Fees run to a fraction of a dollar, which is what makes smaller positions viable here. A strategy involving several transactions is uneconomic where each costs several dollars and works fine where each costs cents, which is why BNB Smart Chain attracts activity that would be priced out elsewhere.
The practical rule is to keep a permanent reserve of BNB in any wallet you use for this, enough for a few dozen transactions. Running out mid-strategy is the ordinary way people find themselves unable to close a position. How to buy BNB covers buying it and withdrawing it to a wallet.
Trading through liquidity pools
The largest category of activity is swapping tokens without an intermediary, and the mechanism is worth understanding because it explains the costs.
A decentralized exchange, often shortened to DEX, holds pools of token pairs, and the price is set by the ratio of what is in the pool rather than by matching buyers to sellers. Swapping moves that ratio, which moves the price, so a large trade against a small pool moves it a long way. That effect is called slippage, and it explains why the same trade costs more on a thin market than on a deep one.
BNB appears in this arrangement in two separate ways. It pays the gas for every swap, and it is one half of many of the pools themselves, since pairing a token against the network's own currency is the most common structure. Most swaps route through wrapped BNB, or WBNB, which is BNB packaged as a standard token so contracts can handle it, and the wrapping usually happens automatically.
Providing liquidity to a pool is the other side of this: you deposit both tokens, earn a share of the trading fees, and accept that the pool rebalances as people trade against it. That rebalancing can leave you with less value than simply holding the two tokens would have, which is a real and frequently underestimated cost. The BNB Chain ecosystem covers the applications where this happens.
Lending, borrowing and collateral
Lending markets let you deposit assets to earn interest and borrow against what you have deposited, with the rates set by how much of the pool is currently borrowed at the time.
Borrowing works entirely on collateral, since nobody involved knows who the borrower is. You post assets worth more than you borrow, and if their value falls far enough relative to the debt, the position is liquidated automatically to repay it. There is no grace period, no call, and no discretion, which is exactly what allows the system to lend to strangers.
BNB serves as collateral on these markets, and that use changes the risk of holding it. Depositing BNB as collateral and borrowing against it means a fall in the BNB price moves you toward liquidation, and doing that during a volatile period is how people lose positions overnight.
The yields on deposits come from borrowers paying interest, which is a genuine source rather than an invented one. What varies is the rate, which moves with demand for borrowing, so a fixed high number advertised as stable deserves a look at where it actually comes from.
Staking and liquid staking tokens
Native staking sits outside the application layer, as part of the protocol: you delegate BNB to one of the 45 validators securing the network and share the transaction fees it earns. BNB staking explained covers how delegation works.
Liquid staking services build directly on top of that. They stake on your behalf and issue a tradeable token representing the position, which can then be used inside other applications while the underlying coins remain staked. That token can be supplied to a lending market or a liquidity pool, which is how yields get stacked.
Stacking is where the risk starts compounding quietly. Each layer adds its own contract risk, and a problem at any level affects everything built on top of it, so a position combining liquid staking with lending and a liquidity pool depends on three sets of contracts working simultaneously. The advertised return reflects the stack, and so does the exposure.
What these applications actually risk
Four things carry most of the risk, and none of them is exotic or unlikely.
Contract failure, because every application is code that can contain errors, and an audit says specific code looked sound to specific reviewers on a specific date instead of guaranteeing anything. Protocols that passed an audit have still been exploited afterwards.
Liquidation, which follows automatically when collateral falls below the required level, with no warning and no discretion, and it happens fastest during exactly the volatile periods when you are least able to respond.
Persistent approvals, because permission you grant a contract to move your tokens usually survives the transaction that requested it, which is why reviewing and revoking old approvals periodically matters as much as where you keep the coins.
Fake applications, since convincing copies of every popular protocol rank in search results, and reaching applications through addresses you saved yourself defeats nearly all of them. BNB scams and fake tokens covers the patterns these copies follow.
Starting sensibly
Three habits do most of the work for anyone approaching this for the first time.
Start with an amount you could afford to lose entirely, because the learning curve here is expensive and the mistakes are permanent. A small position teaches the same lessons as a large one at a fraction of the cost.
Use established applications with long operating histories and substantial value already deposited, since time in production is the most honest evidence available about whether contracts hold up. A new protocol advertising a high yield is still a new protocol, whatever the number attached to it.
Understand where a yield comes from before accepting it. Lending interest paid by borrowers and trading fees paid by swappers are real sources with real explanations, and a return that cannot be traced to one of those is worth declining. Whether BNB is safe sets these risks alongside the others.
Frequently asked questions
What is BNB used for in DeFi?
Four things in total, and the first applies to everything else. It pays the transaction fee for every interaction with every application on BNB Smart Chain. It forms one half of many liquidity pools, usually in its wrapped form as WBNB. It also works as collateral on lending markets, and it can be staked with validators, either natively or through liquid staking services whose tokens are then used elsewhere.
Why do you need BNB even when using other tokens?
Because BNB Smart Chain charges its fees in BNB regardless of what you are doing, so every swap, deposit and approval draws on your BNB balance. A wallet holding a large position in something else and an empty BNB balance cannot transact at all, which is the most common obstacle people meet. Keeping a small reserve of BNB in that wallet solves it permanently.
What is WBNB and why does it appear in swaps?
Wrapped BNB is the coin packaged as a standard token, which lets contracts handle it the same way they handle everything else. Most decentralized exchanges wrap and unwrap it automatically, so people hold it briefly without noticing. It is worth the same as BNB and converts back one for one, and it has to be unwrapped before it can pay a transaction fee.
How does collateral replace a credit check?
Through collateral worth more than the loan itself, posted in advance. You deposit assets, borrow a smaller amount against them, and the position is liquidated automatically if the collateral falls below a required level. That mechanism replaces the credit assessment entirely, and it means a market fall can close your position without warning or discretion.
Are the yields on BNB Chain applications real?
Where they come from lending interest or trading fees, yes, since borrowers and swappers are genuinely paying them. The rates move with demand, so a stable high number deserves scrutiny about its source. Very high yields usually indicate either substantial risk somewhere in the structure or a return being paid from something other than revenue.
What is the biggest risk in using these applications?
Contract failure and liquidation account for most large losses, with fake applications close behind. All three are reduced by the same habits: use established protocols, understand what a transaction does before approving it, keep positions small enough that a total loss is survivable, and reach applications through addresses you saved rather than search results.
Researched and written by the BloFin Academy editorial team with AI-assisted drafting. Updated September 2026. Primary sources include BloFin's Help Center. All facts independently verified against cited documentation current as of September 2026.
This article is educational and general in nature, not financial or investment advice. Cryptocurrencies like BNB carry real risks, including price volatility, smart-contract exploits, automatic liquidation of collateralized positions, and persistent contract approvals. Nothing here is a recommendation to buy, sell, or hold any asset. Do your own research, and consider speaking with a licensed professional before making financial decisions. BloFin does not provide investment advice.