Stanley Druckenmiller and Bill Ackman were buying shares of these tech giants in the second quarter.Buying and holding shares of the best businesses in the world is the easiest way to build wealth over the long term. Some of the largest, most profitable companies in the world also just happen to be in a prime position to benefit from global adoption of artificial intelligence (AI), which is expected to add $15.7 trillion to the global economy by 2030, according to PwC.Investors wondering where to place thei ...