How to Fight MEV, Secure Your DeFi Positions, and Track a Diverse Portfolio without Losing Sleep

I used to blink at block explorers and feel a little queasy. Really. The first time I watched a sandwich attack wipe out a limit order I felt exposed. But that feeling taught me something useful: the Web3 stack—wallets, relayers, validators—doesn’t have to be mysterious or hostile. It can be engineered, and used, to protect users and their strategies.

Here’s the thing. MEV (maximal extractable value) isn’t just an abstract economic idea. It’s a practical risk vector. Bots, searchers, and sometimes miners can reorder, front-run, or censor transactions to extract value. That impacts slippage, execution certainty, and ultimately your returns in DeFi. Short version: if you don’t think about MEV, you will pay for it.

Why MEV matters for DeFi users

MEV shows up in three blunt ways: front-running, back-running, and sandwiching. Front-running is when a faster actor jumps in front of your trade. Back-running is when someone spots your trade and quickly executes complementary logic after it. Sandwiching is the classic two-sided squeeze around your swap. These patterns reduce expected execution value and amplify slippage for users who broadcast raw transactions to the public mempool.

On a deeper level, MEV influences governance, consensus, and decentralization. When block proposers can reliably profit from reordering, it creates incentives that don’t always align with protocol health. So protecting users is both a UX and an ecosystem issue.

Okay, so what do you actually do about it? Let’s get practical.

Practical defenses: from wallets to relayers

First: use a wallet and routing path that simulate and verify transactions before broadcast. Simulation is underrated. It tells you what will happen to your transaction in the current chain state, including slippage and potential revert reasons. Good wallets will run this locally or via a trusted RPC and surface the result. That reduces surprise failures and wasted gas.

Second: private transaction submission. Instead of sending your signed tx to the public mempool, opt for private relayers or bundle services that forward your tx directly to miners/validators or to MEV-aware builders who respect ordering. This reduces exposure to extractive bots. Flashbots popularized this for Ethereum via MEV-Boost; similar private-relay patterns exist across chains now.

Third: use gas and nonce management strategically. Higher priority gas or using replace-by-fee aggressively can outcompete opportunistic searchers. Nonce management—particularly for multi-step strategies—helps you avoid partial execution states that leave value on the table. In practice, that means wallets that let you preview, set, and sign bundles, not just hit “confirm” and hope.

Fourth: bundle logic where possible. If your strategy has dependent trades (like borrow → swap → repay), bundle them into a single atomic execution or send them as an ordered group to a builder so they’re executed together or not at all. Atomics are a powerful antidote to sandwich attacks and race conditions.

How a modern Web3 wallet fits into all this

Wallets are no longer just key managers. They’re execution platforms. A good wallet will do at least three things well: simulate transactions with current state, give private submission options, and provide clear approval controls for ERC-20/ERC-721 interactions. That avoids the accidental “approve unlimited” mistake and lets you revoke approvals later if needed.

I’ve been testing wallets that integrate transaction simulation, approval governance, and private relays. Some are excellent at UX. Some still feel like developer tools. What I’d recommend is picking a wallet that treats transactions as workflows, not just messages. If you want an example of a wallet that puts execution safety front and center, check out https://rabby-wallet.at/ —they emphasize transaction simulation and clearer approval UX, which matters when MEV and approvals are both on the line.

Portfolio tracking: why it’s more than balances

Tracking a portfolio used to mean “how many tokens do I have?” Now you need position-level insights: LP impermanent loss, staked vs. claimable rewards, leveraged positions’ liquidation risk, and pending orders’ exposure to MEV. You also want historical P&L tied to on-chain events so you can see how execution quality affected returns.

Reliable tracking needs robust indexing and cautious assumptions about token pricing sources. Price oracles can be gamed. Multiple feeds, median pricing, and cross-checks (DEX swaps, Chainlink, other aggregators) reduce blind spots. For traders, knowing whether your executed price is the median market price or a bot-inflated level matters a lot.

Finally, integrate alerts for event-driven risks: a governance proposal that affects tokenomics, a sudden drop in TVL for a DEX you use, or a mempool flood that increases MEV risk. Alerts let you decide to delay trades, boost gas to secure ordering, or adjust exposure.

Protocol design notes for minimizing extractable value

Designers can lower MEV by reducing order dependence and increasing atomicity. Batch auctions, randomized order flow, and private auctioning of execution rights all shift rent extraction away from opportunistic searchers. On-chain solutions like frequent call-to-action rewrites, and off-chain sequencing via trusted builders, are evolving. No silver bullet exists—it’s a layered defense problem.

On one hand, more privacy reduces extractable opportunities. On the other, it can centralize power if a single relayer becomes dominant. So measure trade-offs. Decentralization, efficiency, and fairness rarely align perfectly. Thoughtful protocol choices and interoperability between relayers and proposers can strike a practical balance.