We regret to report that Seres Therapeutics shareholders are down 87% for the year. Unfortunately, that's worse than the broader market decline of 20%. Having said that, it's inevitable that some stocks will be oversold in a falling market. The key is to keep your eyes on the fundamental developments. Unfortunately, last year's performance may indicate unresolved challenges, given that it was worse than the annualised loss of 12% over the last half decade. We realise that Baron Rothschild has said investors should "buy when there is blood on the streets", but we caution that investors should first be sure they are buying a high quality business. I find it very interesting to look at share price over the long term as a proxy for business performance. But to truly gain insight, we need to consider other information, too. Take risks, for example - Seres Therapeutics has 2 warning signs we think you should be aware of.