Bitcoin exchange-traded funds are set to start trading as early as Thursday after final registration statements went effective following a months-long approval process with the Securities and Exchange Commission — leaving some to wonder what's next. 

The past few weeks in itself have been eventful leading up to the approvals, but the intrigue doesn't stop there as experts weigh in on what billions of dollars in flows could look like in the coming days and weeks, if a spot ether ETF is next and if this changes the regulatory landscape for crypto.

Flows over the next few weeks

All eyes will be on the expected inflows within the first 24 to 48 hours, said Anthony Rousseau, head of brokerage solutions at multi-asset trading platform TradeStation, in a statement. 

"Projections …