A lot of coins are already trading near their lows and others also down 80-90% from their all time highs that were formed during the last bull run. Even bitcoin has lost around 705 of its value since then. Many alts inlcluding the ones in top 10 are worth investing. Ethereum, cardano, Bitcoin cash, Ripple, etc are such alts. Even many small cap alts are good to invest. You need to make your own choice and be picky while investing.