Now, it will be a smart act to invest money in promising altcoins from the first hundred on the coinmarket, then with the next hype, when prices will rise again you will be ready for maximum enrichment.
selling is not a good time because prices haven't gone up high, it's better to invest in a lot of Altcoin. Reliable and promising Alcoin in the future will make it easier for you to get opportunities, especially investing in various coins, the more opportunities there are.
sell when the market has risen so you are safe even if you only get a little profit, because if you wait until it rises high, sometimes it doesn't match what you imagine, the value may drop again.