September 2024 was a brutal month for DeFi users. More than $120 million was stolen across multiple hacks, including the $27 million Penpie exploit, the $44 million BingX breach, and a $230,000 flash loan attack on Bankroll Network. With Bitcoin hovering around $63,329 and Ethereum at $2,648, the amounts at stake keep growing, but many users still jump into DeFi protocols without basic due diligence. If you are new to decentralized finance, understanding how to evaluate a protocol before depositing your funds could be the difference between earning yield and losing everything.
The Basics
DeFi protocols are software programs running on blockchains that provide financial services without traditional intermediaries like banks. They offer lending, borrowing, trading, and yield farming opportunities that can generate significantly higher returns than traditional savings accounts. However, this comes with a critical trade-off: there is no customer service department, no insurance fund in most cases, and no regulatory safety net. When something goes wrong, your funds may be gone permanently.
The attacks in September 2024 illustrate the variety of risks. Penpie lost $27 million through a reentrancy vulnerability, where an attacker repeatedly called a function before the protocol could update its balances. Bankroll Network lost $230,000 through a flash loan exploit that manipulated price feeds. BingX lost $44 million when attackers breached exchange hot wallets. Each type of exploit targets a different weakness, and understanding these categories is your first line of defense.
Why It Matters
In traditional finance, regulatory bodies, auditors, and insurance mechanisms provide layers of protection. If your bank is hacked, government deposit insurance typically covers your losses. DeFi operates without these safeguards. Smart contracts are immutable once deployed, meaning bugs are permanently baked into the code. The open-source nature of DeFi means attackers can study the code at their leisure, looking for vulnerabilities that developers missed.
The stakes are enormous. DeFi protocols collectively hold tens of billions of dollars in user deposits. A single vulnerability in a widely-used codebase can cascade across multiple protocols, as many DeFi platforms share underlying components or interact with each other through composability. When one protocol fails, others that depend on it can also be affected.
Getting Started Guide
Before depositing funds into any DeFi protocol, work through this checklist systematically.
Step 1: Check for audits. Professional security audits from reputable firms like Trail of Bits, OpenZeppelin, Consensys Diligence, or Certik are essential. Look for audit reports published on the protocol’s documentation site. Multiple audits from different firms are better than one. No audits at all is a dealbreaker.
Step 2: Evaluate the team. Are the developers public and verifiable? Teams with established reputations, published research, and track records of responsible disclosure are far more trustworthy than anonymous developers. Anonymity is common in crypto, but it should lower your confidence proportionally.
Step 3: Review the TVL and history. Total Value Locked indicates how much capital users have trusted the protocol with. A higher TVL suggests more community confidence, but also makes the protocol a bigger target. Check how long the protocol has been operating without incidents. Newer protocols carry higher risk simply because they have not been battle-tested.
Step 4: Understand the tokenomics. Read the protocol’s whitepaper or documentation to understand how its token works. Are there massive team allocations that could be dumped? Are vesting schedules reasonable? Does the token have genuine utility, or is it primarily a speculative instrument?
Step 5: Test with small amounts. Before committing significant funds, deposit a small test amount and walk through the entire user flow: depositing, earning yield, withdrawing. This reveals potential issues with the interface, gas costs, and withdrawal mechanics before larger sums are at risk.
Common Pitfalls
New DeFi users frequently make several predictable mistakes. The most dangerous is chasing unsustainable yields. Annual percentage yields above 20 percent in stablecoin pools almost always involve significant risk, whether from leveraged strategies, impermanent loss, or outright scams. If the yield seems too good to be true, it probably is.
Another common error is ignoring approval permissions. When you interact with a DeFi protocol, you typically grant it permission to spend tokens from your wallet. Unlimited approvals are convenient but dangerous. A compromised protocol can drain all tokens you have approved. Use tools like Revoke.cash to review and limit your token approvals regularly.
Failing to understand impermanence loss in liquidity pools catches many beginners off guard. When you provide liquidity to a decentralized exchange, you can lose money if the price ratio between the two tokens changes significantly, even if both tokens individually increase in value. This is not a hack or a bug, but a fundamental property of how automated market makers work.
Next Steps
After mastering the basics of protocol evaluation, consider diversifying your DeFi exposure across multiple protocols rather than concentrating all funds in one place. Follow security researchers and blockchain analytics firms on social media for real-time alerts about emerging threats. Set up transaction notifications for your wallets so you can respond quickly if something unexpected occurs. Consider using hardware wallets for your primary holdings and keeping only the funds you actively need for DeFi in hot wallets. The September 2024 hacking spree demonstrated that no platform is immune to attack, but users who practice systematic risk management consistently fare better than those who do not.
Disclaimer: This article is for educational purposes only and does not constitute financial advice. Always conduct your own research and never invest more than you can afford to lose.
the $120M figure across September alone is wild. and most of these were preventable with basic audits. people really need to stop apeing into unaudited contracts
120M across September and the common thread is basic reentrancy and flash loan vectors. these are solved problems
Penpie was literally a reentrancy bug in 2024. thats like the oldest exploit in the book. no excuse for that
^ this. if the protocol cant even handle basic reentrancy guards, what else are they missing? the checklist approach here is solid tho, bookmarking for newbies i send this to
0xpleb.eth reentrancy in 2024 is embarrassing. openzeppelin has guards for this that take 2 lines of code to implement
reentrancy in 2024 is basically shipping without seatbelts. openzeppelin has had the guard since 2018. no excuse
2 lines of code to prevent reentrancy and teams still ship without it. the audit industry needs a better standard
Felix R. the audit industry doesnt need a better standard, it needs teeth. right now an audit is basically a suggestion
audits are basically legal cover. the firm gets paid either way and the protocol gets a badge. nobody is accountable when it breaks
Theo M. audits as legal cover is exactly right. the firm gets paid, the protocol gets a badge, users get rekt. nobody is accountable
the checklist is great but lets be real. most DeFi users skip reading the docs entirely, they see a 15% APY on defillama and ape in
yield_chaser nailed it. nobody reads the docs. defillama APY is the only research most people do
$44M from BingX alone and they still operate like nothing happened. crazy how fast the space normalizes theft
normalizes is the right word. $44M from BingX barely made headlines because everyone is desensitized at this point
Anika H. bingx was a central exchange hack not a defi exploit. different risk entirely. you cant audit an operator