Thursday was a generally poor day for the stock market, with the Nasdaq Composite taking a bigger hit than most other major benchmarks. A combination of factors affected the markets, including the perceived danger of tighter regulation in the technology industry, concerns about intragovernmental turmoil in Washington, and more general questions about whether the bull market can reach its 10th anniversary without reversals bigger than the corrections we saw earlier in the year. In particular, some key individual stocks were under even greater pressure due to company-specific issues. Micron Technology (NASDAQ:MU), Twitter (NYSE:TWTR), and Wynn Resorts (NASDAQ:WYNN) were among the worst performers on the day. Here's why they did so poorly.

Micron gets chipped

Micron stock fell another 10%, adding to recent losses as analyst companies started to pull away from what had once been one of their strongest recommendations. Analysts at Baird cut their price target on Micron by $25 to $75 per share, believing that the upward phase of the business cycle for memory prices is likely to give way to a downward reversal in the near future. Analysts at Morgan Stanley largely agreed with that assessment, and even though some other professional investors on Wall Street believe that the declines in Micron stock already reflect a pullback from recent success, investors in the chip company know all too well just how big the up and down moves can be when longer-term trends in the industry change course.

Three memory semiconductor chips with Micron logos on them.

Image source: Micron Technology.

Twitter goes to Washington

Shares of Twitter lost 6% after the social media company's executive testimony before Congress raised nervousness among investors. CEO Jack Dorsey testified on Capitol Hill, making comments related to allegations of election tampering, security flaws, and political bias on the Twitter platform. Despite moves to remove problematic accounts, Twitter remains under fire for allegedly being harder on those with conservative viewpoints. Moreover, some shareholders haven't been sure that Twitter's moves would be enough to quell dissent, while others fear that the measures could hurt the social media company's ability to grow and thrive in the industry.

Wynn keeps falling

Finally, Wynn Resorts stock dropped another 9%, compounding declines that the casino resort giant has suffered over the past several months. Many of the worries surrounding Wynn focus on conditions in China, with the casino industry's bastion of growth in Macau potentially under threat if growth in the Chinese economy continues to slow. Macau's monthly numbers for August were solid, but Wynn is facing a critical time right now, especially with the eventual fate of its Boston resort still in doubt. With so much uncertainty, investors just don't seem willing to gamble on Wynn's future -- even with share prices at their lowest levels in more than a year.

Dan Caplinger owns shares of Wynn Resorts. The Motley Fool owns shares of and recommends Twitter. The Motley Fool has a disclosure policy.