One month after its initial public offering, social media darling Twitter is enjoying a flush of investor interest in its shares—the company's stock price rose more than 10 percent Monday to trade near its all-time high of $50.09.
"Mad Money" star Jim Cramer says Twitter's strength caught him by surprise, but he notes that an advisory firm's push for short-selling the stock may be helping to drive the shares up.
On Thursday Twitter officially began allowing marketers to show individually-tailored ads on social media feeds, based on websites the user has previously visited. The cookie-based targeted ads, as they are known, are expected to fetch higher ad prices.
The company also said it would launch a text-only version of the service that would be available to people with entry-level mobile phones that cannot access the Internet.
—CNBC.com. Reuters contributed to the article.