The answer is that the trust fund is populated with special non-marketable securities whose value is not subject to the vicissitudes of the market.

FORBES: A Modest Proposal to Avoid Debt Limit Disaster

As with most marketable currencies, equity in a biotech can suffer from deviations from this underlying data-supported value, which can result in over-pricing of assets that lack the intrinsic quality or robustness.

FORBES: Unleashing Biotech Innovation With The Currency of Entrepreneurship