Recently, everyone has been talking about block builders and bundles, and it sounds pretty esoteric. In fact, retail investors only need to know the "sufficient version": the transaction you send may not be included in the block in the order you confirm it; it might be bundled together with others and inserted all at once. Who goes first or last often depends on how the packer queues and how they collect tips. To put it simply, remember two things: don't use market orders to aggressively trade in low-liquidity pools, as slippage and failure fees will teach you a lesson; and when you see prices being swept back and forth in an instant, don't compete with speed or scripts—wait for a quieter period before acting.