By drip feeding. Buying smaller amounts of several stocks and building holdings slowly so as not to spook the market.

A bit like building a wall ; one brick at a time on each course.

I was thinking about how buffet has to buy tens of millions of stock just to make it worth his while. But if you put in an order for 5 million shares wont it just inflate the price much greater than its intrinsic value? Therefore he would be forced to buy expensive shares just because his own demand drives up the price.