Recently, people keep asking how much retail investors need to understand about block builders, bundles, and such. To be honest, there's no need to memorize a bunch of terms; just remember one thing: the transaction you send out may not be included in the chain in the order you expect. Others can "bundle" and insert your transaction in the middle to earn a small arbitrage.

Yesterday, I saw a swap (0x7c…a1) in the mempool waiting for two or three blocks, and the final transaction price clearly dropped. Most likely, it was inserted into a bundle by someone.

My simple rule is: for large or slippage-sensitive transactions, don’t go naked; use private relay/protection modes if possible. If it’s not urgent, set limit orders or split into batches—don’t go all-in at once. You don’t need to study who is a builder or proposer; just incorporate the risk of "I might be sandwiched" into your strategy.

By the way, this reminds me of the collapse of some blockchain games—inflation + studio manipulation, coin prices spiraling, and retail investors ending up as liquidity… Anyway, I now approach any "auto-earning" scheme with the worst-case scenario in mind. That’s all for now.