Wisconsin Investment Board Disclosed $162.9 Million in Spot Bitcoin Funds

The State of Wisconsin Investment Board disclosed on May 14, 2024 that it held $162,854,998 in two U.S.-listed spot bitcoin products at the end of the first quarter. Its Form 13F reported 2,450,400 shares of BlackRock’s iShares Bitcoin Trust, or IBIT, valued at $99,167,688, and 1,013,000 shares of Grayscale Bitcoin Trust, or GBTC, valued at $63,687,310, as of March 31.

Coinburn calculates the combined value by adding the two fair-value entries in the filing. The disclosure mattered because a state investment agency responsible for public retirement and other trust assets had used the newly available exchange-traded route to bitcoin exposure at substantial scale.

A public manager entered the spot-product market

The Securities and Exchange Commission had approved exchange rule changes for multiple spot bitcoin exchange-traded products on January 10, 2024. IBIT and the converted GBTC began exchange trading on January 11. The Wisconsin filing therefore captured positions established during the products’ first calendar quarter of trading.

The structure is important. SWIB reported shares in trusts that held bitcoin; it did not report bitcoin held directly in a wallet. Listed shares offered conventional brokerage, custody, valuation and reporting channels, while leaving investors exposed to bitcoin-price movements, trust expenses, tracking differences and product-specific custody arrangements.

SWIB’s January 2024 institutional description said it managed the Wisconsin Retirement System, the State Investment Fund and other state trust funds. The May 14 filing did not identify which underlying Wisconsin fund or investment mandate owned the IBIT and GBTC shares. It is therefore more precise to call this a SWIB holding than to assign the entire position to a particular pension account.

The filing was large, but its denominator needs care

The 13F contained 2,216 line items with a reported fair value of $37,896,465,042. The two bitcoin-product positions represented about 0.43% of that reported total: $162,854,998 divided by $37,896,465,042.

That percentage is a Coinburn calculation, not a figure supplied by SWIB. It also is not a measure of the positions against all assets managed by the agency. Form 13F covers specified securities, principally U.S.-traded equities and exchange-traded fund shares; it does not provide a complete inventory of bonds, private assets, cash, derivatives or every other investment category.

The measurement date was March 31, not May 14. Form 13F shows quarter-end shares and fair values, but not purchase dates, cost basis, subsequent trades or the investment thesis. The filing marked both positions as subject to sole investment discretion and reported sole voting authority. It did not establish that SWIB still held the same quantities when the document became public.

Why the disclosure mattered

Contemporaneous reporting identified the filing as the first spot-bitcoin-product disclosure by a U.S. state investment board. That made it a visible institutional-adoption marker less than four months after the SEC’s approvals. The significance lay less in the percentage of one regulatory filing than in the identity of the manager: public fiduciaries generally operate under formal mandates, oversight and risk controls.

The record did not show that other state funds would follow, that Wisconsin had endorsed bitcoin as money, or that the positions would improve retirement outcomes. It also did not reveal whether SWIB used other holdings or derivatives to offset any exposure.

No event-day bitcoin return is attributed to the disclosure. Cryptocurrency trades continuously across fragmented venues, while the filing reported stale quarter-end securities positions and offered no causal market evidence. The defensible May 14 conclusion is narrower: SWIB publicly revealed a roughly $162.9 million exchange-traded bitcoin exposure, bringing a new category of public institutional manager into the spot-product record.