Mike Bloomberg is self funding his campaign and with a personal fortune of $65 billion. His campaign spending could be essentially limitless. With this amount of money he could radically outspend Trump (who only spent 0.3 billion on his 2016 campaign) and seriously upset the campaign ad market prices thanks to the competitive bidding process.
Under current law, losing candidates are allowed to donate "unlimited transfers to a local, state, or national political party committee." Does this mean that if the DNC nominates another candidate, Bloomberg could donate his billions directly to the DNC to help Biden or Bernie defeat Trump? Or is he limited by campaign finance law to only donate the maximum of $2800? Does this change if he drops out, or does he technically still have to be running to avoid campaign finance law violations?
Update: Bloomberg has dropped out. Previously he has pledged to pay for his nearly 500 staffers to continue working through November to support whoever the DNC nominates. They will be "independent" so this doesn't violate campaign finance law.