Tesla Motors owner Elon Musk began to move share prices when he joined Twitter in 2013, beginning with a tweet hinting at a future company announcement. The shares of Tesla Motors immediately increased by 2.4%.
Donald Trump is probably the most notorious tweeter out there, using the platform for everything from policy ideas to personal attacks. Just one example is when he tweeted about renegotiating prices for products from Lockheed Martin and Boeing, causing an immediate drop in their share prices.
Oprah has been America’s guru on pretty much everything for the past few decades, so when she first tweeted about joining Weight Watchers, the share price of the weight loss company rose nearly 20%. Weight Watchers continues to have high share prices, currently double what they were before Winfrey’s market-shaking tweet.