https://arstechnica.com/tech-policy/2017/07/twitters-stock-plunges-as-user-growth-stalls/

Several years ago, Twitter seemed like it would be the social media darling of the decade. Founders had dreams of being the first Internet company to reach one billion users, making it "the pulse of the planet."

That's not going to happen, and investors are cluing in. Twitter had 328 million average monthly active users, or MAU, in the three months ending in June, which is unchanged from the previous quarter. The company's shares were down more than 10 percent this morning on the news.