BUSINESS COMBINATIONS - Narrative (Details) $ in Millions				3 Months Ended
	Jun. 02, 2025 USD ($)	May 12, 2025 USD ($)	Feb. 26, 2025 USD ($) shares	Sep. 30, 2025 USD ($)	Jun. 30, 2025 USD ($)	May 12, 2025 $ / shares
TradePMR
Business Combination [Line Items]
Consideration transferred			$ 175
Increase to receivable					$ 3
Decrease to other current assets					1
Decrease to other non-current assets					1
(Decrease) increase to goodwill					$ (1)
Weighted average useful life			9 years 9 months 3 days
TradePMR | Common Class A
Business Combination [Line Items]
Number of unvested shares issued (in shares) | shares			2,049,711
Business combination, shares granted value			$ 100
Business combination, post acquisition service period			4 years
Bitstamp
Business Combination [Line Items]
Consideration transferred	$ 224
(Decrease) increase to goodwill				$ 2
Weighted average useful life	7 years 29 days
WonderFi
Business Combination [Line Items]
Business combination, price per share (in dollars per share) | $ / shares						$ 0.36
Price of expected acquisition		$ 180