Lending Protocols: Be the Bank, Get Rekt Like One
Deposit crypto, earn interest. Simple, right? Until liquidations hit and you realize you were the liquidity all along.
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You know what banks do, right?
They take deposits. Pay you 0.5% interest. Then lend that money at 15% and pocket the difference.
Now imagine you could BE the bank. Keep all the interest for yourself.
That's DeFi lending. And it's both brilliant and terrifying.
The basics
You have ETH sitting in your wallet doing nothing. Sad ETH.
You deposit it into Aave or Compound. Now it's working.
Borrowers come. They want to borrow your ETH. But here's the twist - they have to deposit collateral worth MORE than what they borrow.
Wait, what? Why would anyone borrow $100 if they need to lock up $150?
Good question. The answer reveals everything about DeFi.
Why over-collateralization exists
In traditional finance, banks lend based on trust. Your credit score. Your job. Your identity.
In DeFi? No identity. No credit score. No trust.
The ONLY thing protecting lenders is cold, hard collateral that can be liquidated instantly if shit hits the fan.
Someone wants to borrow $100 worth of DAI? They better lock up $150 worth of ETH. If ETH drops and their collateral falls below a threshold? Automated liquidation. Gone.
It's trust-minimized. Beautiful, really. But also brutal.
Why people borrow anyway
Let's say you have 10 ETH. You're bullish. You think ETH is going to $10,000.
You could just hold. But that's boring.
Or... you deposit your 10 ETH as collateral. Borrow $20,000 in stablecoins. Buy 10 more ETH with that.
Now you have exposure to 20 ETH worth of upside.
If ETH moons? You win big.
If ETH dumps? You get liquidated. Your original 10 ETH? Gone. Thanks for playing.
This is leverage. And it works until it doesn't.
The liquidation game
Here's where it gets spicy.
When someone's collateral ratio drops below the threshold (say 150%), their position becomes liquidatable.
Anyone can be a liquidator. You spot an underwater position, you can pay off part of their debt and take their collateral at a discount.
Usually 5-10% discount. Free money for liquidators.
Not so free for the person getting liquidated. They lose their collateral AND the liquidation penalty.
During market crashes, this creates cascades. Price drops → liquidations → forced selling → price drops more → more liquidations.
March 2020. Black Thursday. ETH crashed 43% in 24 hours. Liquidations everywhere. Some people lost everything because the network was so congested their transactions couldn't save their positions in time.
Fun times.
The interest rate game
Supply and demand. That's it.
Lots of people want to borrow ETH? Interest rates go up.
Nobody borrowing? Rates go down.
During NFT mints, ETH borrowing rates can spike to 50%+ for a few hours. Degens willing to pay anything to mint that overpriced JPEG.
As a lender, you love high rates. As a borrower, you need to watch constantly. That 3% rate can become 30% overnight.
The risks nobody talks about
Smart contract risk. Aave holds billions. A bug means billions gone.
Oracle risk. These protocols rely on price feeds. If the oracle says ETH is $1, liquidations happen at $1. Doesn't matter what the real price is.
Governance attacks. Someone buys enough governance tokens, proposes malicious changes, drains the protocol. Beanstalk lost $182 million this way.
Liquidity crises. Everyone wants to withdraw at once. Not enough liquidity. You're stuck.
The yields look safe. The risks are not.
Who actually makes money?
Liquidators. MEV bots. Sophisticated actors who can:
- Spot underwater positions before anyone else
- Execute transactions in microseconds
- Exploit market dislocations
You? You earn 3% yield while taking risks most people don't understand.
Is that a good trade? Only you can answer that.
The bottom line
DeFi lending is powerful. It enables leverage without intermediaries. Capital efficiency. Permissionless access.
But it's also a PvP arena disguised as passive income.
If you're lending:
- Understand the risks
- Spread across protocols
- Monitor your positions
If you're borrowing:
- Keep your health factor safe
- Have a plan for crashes
- Don't use max leverage
The code doesn't care about your feelings. It will liquidate you at 3 AM on a Sunday if the math says so.
Be the bank. Just don't go bankrupt like one.
Next: Yield Farming - the art of chasing APY until it disappears.