I do not invest in ICOs or projects that in its early phase, I only putting my money on altcoins that are listed wherein there are some guarantee that my money can make money but still there are risks when choosing an altcoin and that skill is important to learn because there are investors and traders who do not know how to pick a right altcoin. A good altcoin have a billion market capitalization where its daily volume is also big where it indicating that there are many people willing to purchase that coin.
A good altcoin does not need to have a capitalization of one billion dollars, this is overkill. A good altcoin should have a capitalization of at least 500k - 1kk, this will be enough to cover liquidity.
In addition, everything will depend on the circulating number of coins. Of course, the lower the liquidity, the higher the volatility.