Mean reversion is where the investor assumes that the price of a coin will remain at an average price level over time.  Upward trends, and downwards trends, are expected to revert back to the average over the long haul. This means you need to know the charts well and be able to figure out what the average price for the cryptocurrency you intend to trade in. When the coins are less than the estimated average that is when one wants to make a few purchases. When the price is higher than the average it is expected to drop back down to the mean price and that would be the time to sell.  Of course, figuring out just when to sell is the trick, and that is where the gamble comes in.
What’s important to consider as crypto evolves is to learn everything (or as much as possible) for yourself. Crypto coins all offer white papers to the public (though they’re not always easy to find). They’re for a scientific audience, but you’ve probably read worse if you have a university degree. Find them and read them. Don’t understand something, ask a question.
Always pay attention to Bitcoin. Most altcoins (every cryptocurrency except Bitcoin) are pegged more closely to Bitcoin than Asian currencies were to the USD during the Asian Financial Crisis. If Bitcoin price pump drastically, altcoins price can go down as people try to exit altcoins to ride the BTC profits; inversely, if Bitcoin prices dump drastically, altcoin prices can go down, too, as people exit altcoins to exchange back into fiat. The best times for altcoin growth appear when Bitcoin shows organic growth or decline, or remains stagnant in price.