[FrustratedMonky]

"(GDP) measures the total market value of final goods and services produced"

It can be circular.

MS invests 5 billion in OpenAI.

OpenAI invests 5 billion in MS.

Do we have 10 billion now?

[valleyer]

No goods or services were produced in your example, so GDP would not be affected. Purchases of securities are not goods or services.