Is e.l.f. Beauty stock too cheap to pass up right now?Buying a top growth stock on weakness can result in fantastic gains for long-term investors. The key is to understand why a stock may be struggling. If it's due to market or industry-related factors, and the underlying business remains in solid shape, it can be an optimal time to invest in a struggling stock.One growth stock that's been under pressure in recent months is e.l.f. Beauty (ELF 1.54%). Although the company has been posting strong results, it' ...