On an extremely volatile asset, assuming the price returns to the price at which you bought it, there is a trading strategy that makes a profit, as opposed to buying and holding (which would not profit in our example).
Here's a simple explanation https://blog.enigma.co/is-there-a-free-lunch-in-the-crypto-markets-c4aa331443f1

Imagine you start with $1,000, $500 in stock and $500 in cash. Suppose the stock halves in price the first day. This gives you a $750 portfolio with $250 in stock and $500 in cash. This is now lopsided in favor of cash. You rebalance by withdrawing $125 from the cash account to buy stock. This leaves you with a newly balanced mix of $375 in stock and $375 in cash.
Now repeat. The next day, let’s say the stock doubles in price. The $375 in stock jumps to $750. With the $375 in the cash account, you have $1,125…
… After a dramatic plunge, the stock’s price is back to where it began. A buy-and-hold investor would have no profit at all. Shannon’s investor has made $125.

If you do a little math, you'll find that transaction fees will kill this trading strategy.   If you pay transaction fees on the order of 0.2% (like crypto exchange fees), then balancing small moves like 5 or 10 percent will actually lose you money.  The asset has to be very volatile, and it's only worth rebalancing after big moves such as in the example.
Also, you're going to lose money in a bear market, unless you have the resources to hang on for years until the asset's price returns to where you bought it (if it ever does).