The only thing I can think of is monitoring of all transactions.
Step 1: Buy a lot of bitcoin.
Step 2: Convince/bribe the President of El Salvador to make bitcoin the legal tender.
Step 3: Bitcoin goes up because "OMG legal tender status" even though it is in a super minor country that was de facto using the USD as currency anyway.
Step 4: Sell your bitcoin at a profit due to the events of step 3.
Step 5: Who cares about what happens after step 4.
BTC price swings occurs due to institutional buying (or selling) which are generally triggered by macro conditions. Nothing else triggers it because the market cap is too large to move on minor news.
Finally, an opportunistic Bitcoin trader wants Bitcoin to go down, not up. So that they can buy more.
With traditional bank accounts there's usually a whole circus of verifying your real identity involved that's directly tied to the account.
While getting a BC wallet involves none of that, heck, it can probably be automated to such a degree that asking the question "Who actually owns the wallet created by a bot?" could become an interesting legal conundrum.