It does not matter at what point you enter the market for a coin if you believe in the long-term. Bitcoin was once expensive at $1; it was then expensive at $10; people could not believe it when it hit $100; people could not believe it when it hit $1,000 and when it hit $10,000 they called it a bubble. It could be $25,000 next year or drop back below $5,000. My only advice here is not to chase something during a parabolic upwards move because it will almost certainly come back down.
There are a number of tools you can use to maximize profits and minimize risks, such as margin trading, leverage, and stop-loss orders. Shorting Bitcoin and other cryptocurrencies can be done in a variety of ways. Just looking at the Bitcoin price chart for early 2018, you can see that those that spotted the downward trend in mid January and made a short trade would have made 40% profits by exiting one month later.
Cashaa is more than it's CAS Token cryptocoin. It's a centralized, completely free cryptocurrency exchange where users can exchange their online coinage into any other cryptocoin quickly and easily. Take a look at their site and you will see that the CAS Token is backed by a dynamic exchange economy that means it has massive long-term potential as an investment - because it's a cryptocoin that works with competing currencies instead of trying to beat them.
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.