You probably want to donate any Manifold currency this week

I tend to agree with your co-founders on this one.

Manifold users don't actually cash out that much, so we shouldn't actually need that much cash on hand. 

I am not sure that the behavior of past Manifold users in a play-money economy where the only cash-out was to charity is a reliable guide to how future users will react to in a ~real-money environment.

Another point Zvi raised is that very few online sportsbooks maintain enough cash on hand to fully pay out all users -- it just doesn't make business sense to do this, you grow more slowly if you commit to holding extra cash.

When we're talking about play money potentially redeemable for charitable donations, that is one thing, especially where the vast majority was ~freely obtained (as opposed to being purchased with cash. If people can't donate play money they were largely given for free, that doesn't keep me up at night too much. It's something different where the quasi-cash was largely purchased with real cash (or obtained in wagers of quasi-cash that was largely purchased with real cash). In the latter case, I think you have to be prepared for the risk of a bank run.

The equity value of Manifold dominates the cash considerations (we last raised at $40m valuation), so from our business perspective we can eventually back assets just by raising more. 

Maybe, but conditioned on there being a run on the bank, Manifold equity would not provide a solid backstop for customer claims. If you are in a bankrun situation, there is a pretty decent possibility that Manifold equity is either illiquid or ~worthless. You might be hard-pressed to find buyers either because of the underlying facts that led to the bankrun or due to skepticism about the value of a business whose customers are in a panicked rush for the door. 

Moreover, the base rate of young startup failure is pretty high, so there could be a number of scenarios in which a run makes sense. If I thought Manifold might be going under soon, and my quasi-cash was backed only to a limited extent, I think I'd rather exchange my quasi-cash for real cash ASAP. 

Perhaps you could get an irrevocable line of credit for the next ~2 years backed by a certain amount of equity? If you can, then that could back the quasi-cash liabilities. If you can't, is evidence that you can't get a sophisticated lender to accept the equity as collateral also evidence that Manifold users shouldn't accept it as backing? 

I guess another way of saying this is that I think Manifold should treat quasi-cash holders as ~depositors, and thus should be unwilling to expose them to more than a tiny risk of loss due to anything other than bad trades on Manifold.

Manifold users don't actually cash out that much, so we shouldn't actually need that much cash on hand

This omits why Manifold users didn't cash out much: return rates were unsustainably high. Ponzi schemes manage cash flow at the expense of profit

Yeah - though in practice the charity payouts are transferred once a quarter anyways, so a month or two delay in rolling out payouts wouldn't change the results much.

In any case, definitely think now is a great time as any to do your charity allocations, given our general uncertainty on how all of this will look!

(I'm pretty bullish on sweepstakes payouts actually happening, I think like 80% chance this year. If they don't, then probably something like the charity program would make sense again)