Yep, so long as the price is fair. You owned x/(Tesla^). Now you own x/(Tesla^ + 500M). (Tesla + 500M)>(Tesla) so your share is proportionally smaller. Put ano

Yep, so long as the price is fair. You owned x/(Tesla^). Now you own x/(Tesla^ + 500M). (Tesla + 500M)>(Tesla) so your share is proportionally smaller. Put another way, you own a share of tesla. The day after the offering, Tesla has 500MM more in the bank and you own a percentage of that money. Real life is complicated in all sort of ways. Demand for shares does not perfectly trace inherent value (an unknown number). The action could act as a signal to investors to buy or sell ("They need money because they're growing so fast!" or "They're bleeding cash, run!."). But theoretically, it's supposed to be perfectly fair to shareholders ^Tesla = all Tesla assets the day before the offering.