Bill Ackman Built a $2.4 Billion Stake in Microsoft, Calling It a "Core Holding" Bought at a "Highly Compelling Valuation." Here's Why He's Betting Big on Big Tech.

Key Points The closely followed investor started loading up on the stock earlier this year. In dollar terms, Microsoft became Pershing Square's second-largest tech holding. 10 stocks we like better than Microsoft › Earlier this year, Pershing Square (NYSE: PS) founder and CEO Bill Ackman piled into a stock well-known not only to tech investors, but the general public at large: Microsoft (NASDAQ: MSFT) . Missed Nvidia in 2009? This Rare Signal Is Flashing Again. In 2009, a "Double Down" signal flashed for a little-known chipmaker called Nvidia. For the first time in years, that same "Total Conviction" signal is flashing for a company 1/100th the size of Nvidia.