Couple things going on here. let’s split them apart.

You buy 1 BNB at $200 on Day 1 and invest at 19% for 7 days.

Day 7… you have 1.19 BNB.

But BNB has dropped by 19%, which implies that a $200 BNB is now $162.

So you have 1.19 BNB at $162, which means you’re investment is worth about $193. So you would be slightly behind.

Whenever an asset price falls by X%, it always has to gain some number more than X% to break even.