BlackRock’s Strategic Income Opportunities Portfolio, one of the firm’s own in house mutual funds, has increased its exposure to bitcoin through additional purchases of the iShares Bitcoin Trust (IBIT) exchange-traded fund (ETF), according to the latest SEC filing.

A new filing shows the portfolio held 2,397,423 IBIT shares worth $155.8 million as of Sept. 30, up 14% from the 2,096,447 shares reported at the end of June.

The fund is an unconstrained bond portfolio that moves across government debt, corporate credit, mortgages, emerging markets and cash-like assets, while its flexible mandate allows it to add nontraditional holdings such as ETFs when they support its total return and diversification goals. This structure is what enables the fund to include IBIT alongside its fixed income mix.

IBIT has also been in the spotlight this week after Nasdaq ISE filed to lift the position limit for IBIT options to one million contracts.

Fintel data shows institutional ownership of IBIT rising steadily month over month, now at its highest level since launch with over 400,000,000 shares in total institutional ownership.

Bitcoin BTC$90,530.07 has climbed to over $91,000 on Friday, and IBIT is up about 2% in premarket trading at roughly $52 per share.