The biggest names in finance gave their blessing to the AI computing buildout this week, partnering with chipmaker Nvidia to promote the company's computing capacity as an " investable asset class ." Larry Fink, CEO of BlackRock, one of Nvidia's financing partners, compared Nvidia's computing power assets to the "mortgage-backed securities market in the 1970s." The financing announcement immediately raised questions about more circular financing , but investors say the bigger issue is how exactly to value the assets that will be used as collateral for investments that are already straining the resources of capital markets . While auto loans…