SoftBank Group's prospective high-yield bond offering, poised to rank among the largest ever, has drawn preliminary subscription interest exceeding $20 billion, according to sources familiar with the matter. Investors are scrambling to secure the potentially record-setting yields that the transaction could deliver, as SoftBank intends to use the proceeds to fund its investment in OpenAI.

The current demand figures represent early, non-binding indications of interest from investors and serve as an initial barometer ahead of the final pricing, the sources stated. Pricing for the deal remains slated for Thursday. The sources requested anonymity as the details were not meant to be publicly disclosed.

Other sources reported on Monday that SoftBank is targeting the raise of over $11 billion in equivalent funds through this transaction, which includes $10 billion in U.S. dollar-denominated debt and €1 billion ($1.1 billion) in euro-denominated notes. There is no cap on the offering size, and a final determination has not yet been established, the sources noted.

A representative for SoftBank, replying to queries via email, stated, "We have launched the $10 billion and €1 billion offerings, and the process is proceeding very smoothly with considerable demand. Aside from that, any remarks regarding the deal's size are purely speculative at this stage, and we have no intentions to expand the offering."

This deluge of investor appetite underscores the market's fervor for high-yield debt from a name like SoftBank, particularly when tied to high-profile ventures such as OpenAI. The final pricing remains the next critical step, subject to how the order book evolves in the coming hours.