In Wednesday's analysts' actions, Wall Street firms are making bearish calls on Twitter (TWTR), GoPro (GPRO) and Oracle (ORCL). JMP Securities downgraded Twitter to MARKET PERFORM from MARKET OUTPERFORM citing limited visibility into engagement growth. What analysts mean by this is that even though new management is a plus, engagement growth may stay below industry peers'. As a result, this may impact Twitter's monetization long term. The same firm lowered Oracle's rating to MARKET UNDERPERFORM from MARKET PERFORM with a $31 price target. There's some tough competition from Amazon Web Services, the firm said. Adding to that, it appears customers aren't really satisfied with Oracle's pricing and auditing policies. Another company got hit with a downgrade. Piper Jaffray cut GoPro's rating to NEUTRAL from OVERWEIGHT and dropped its price target by more than half to $25 from $54. Analysts said they're seeing some recent volatility in the stock. On top of that, it appears consumer demand is softening and there are 'weakening trends in the GoPro index on Amazon.' TheStreet's U-Jin Lee reports in New York.