BlackRock and Bitcoin ETFs have helped stabilize the price of Bitcoin, according to Bloomberg analyst Eric Balchunas.There are speculations that BlackRock uses Coinbase's Bitcoin IOUs to manipulate the market and trigger price declines.Claims have emerged that Coinbase's actions with Bitcoin IOUs might be important in the erratic fluctuations of BTC.Coinbase CEO Brian Armstrong denies providing BlackRock with special access to BTC borrowing rights.