Since they are debt-free they can use the billions to buy US Treasuries or similar and use the interest as revenue for profitability or a dividend, for as long as they want. If the share price continues to go up and they issue more shares then they can further increase their interest revenue from treasuries.

tee hee hee

the timing of the increase in volume corresponds to the Heat Lamp Theory’s conjecture, although there may have been other factors as well