SoftBank is looking for a $10 billion margin loan collateralized by OpenAI shares at a rate of SOFR+425 basis points as its leverage structure becomes more complex.

      Summary: SoftBank is in the process of securing a $10 billion margin loan using its OpenAI shares as collateral, with an interest rate of SOFR + 425 basis points (approximately 7.88%) and a two-year term with a potential one-year extension. This loan adds to a $40 billion bridge loan from March, elevating SoftBank’s overall pledge to OpenAI to about $64.6 billion for a 13% ownership stake. With OpenAI valued at $852 billion, this stake could reportedly be worth around $110 billion, but S&P has downgraded SoftBank’s outlook to negative (BB+) due to a $32 billion funding shortfall anticipated over the next two years.

      On Wednesday, Bloomberg reported that SoftBank is looking to secure a $10 billion margin loan backed by its OpenAI shares, which would further increase its debt load in what has become the most leveraged investment in artificial intelligence history. The proposed loan features a two-year term with an option for a one-year extension and carries an interest rate of about 425 basis points over the secured overnight financing rate (SOFR), equating to near 7.88% based on current rates. The loan is not yet finalized, and specific lenders have not been disclosed. It is known that SoftBank is using paper wealth in a private company to finance further investments in the same firm, creating a recursive leverage structure that could function effectively until it does not.

      This is not SoftBank’s first margin loan nor the most intricate financial arrangement of the year. In March, the company secured a $40 billion bridge loan underwritten by JPMorgan Chase, Goldman Sachs, Mizuho Bank, Sumitomo Mitsui Banking Corporation, and MUFG Bank, intended for a $30 billion additional investment in OpenAI and for general corporate purposes. The bridge loan began a soft launch phase in mid-April, inviting more lenders to contribute approximately $5 billion each. The $10 billion margin loan would be added on top of this. Currently, SoftBank’s total debt is approximately 20.45 trillion yen, equivalent to about $135 billion.

      SoftBank’s total investment in OpenAI will reach about $64.6 billion once the $30 billion follow-on closes, giving it around 13% of the company. The initial investment, set to conclude by late December 2025, amounted to between $40 to $41 billion: $7.5 billion in direct investment, $11 billion arranged with co-investors, and a final tranche of $22 to $22.5 billion. To finance this stake, Masayoshi Son sold SoftBank’s entire Nvidia position for $5.83 billion and $12.73 billion in T-Mobile shares between June and December 2025. He then borrowed $40 billion more and is now seeking to borrow an additional $10 billion.

      The notional value of the collateral has fluctuated considerably since the initial investment. SoftBank’s original $40 billion was based on OpenAI’s March 2025 valuation of $300 billion pre-money. By March 2026, OpenAI's record funding round closed at an $852 billion post-money valuation, bolstered by Amazon's $50 billion, Nvidia's $30 billion, and SoftBank’s own $30 billion follow-on investment. At this valuation, SoftBank’s 13% stake is notionally valued at around $110 billion, making a $10 billion margin loan seem relatively small, approximately 9% of the collateral’s paper value. The concern is how much that paper is truly worth if conditions change.

      Historically, when SoftBank borrowed $8 billion against its Alibaba stake in 2018, the interest was LIBOR plus 150 basis points, with ten banks participating. Alibaba was publicly listed on the New York Stock Exchange, allowing lenders to sell shares on the open market with relative ease if SoftBank defaulted, which informed the interest rate.

      Conversely, the OpenAI margin loan is priced at SOFR plus 425 basis points—nearly triple the spread. This discrepancy stems not only from the broader economic context but more significantly from the nature of the collateral. OpenAI is a private entity, meaning its shares do not trade publicly. Secondary market transactions are rare, unclear, and require company approval. OpenAI’s $852 billion valuation is being questioned by its investors, with secondary market data indicating a five-to-one ratio of sellers to buyers. If SoftBank defaults, lenders would own shares in a private company that are difficult to sell, with a valuation that is already being scrutinized in a sector where sentiment can shift rapidly. The extra 275 basis points spread compared to the Alibaba loan reflects the banks' assessment of that risk. Whether this is sufficient compensation is an unresolved issue.

      As of December 2025, SoftBank’s loan-to-value ratio was 20.6%, and recent estimates position it around 19%. The company has set