That money may not be earning much, but it isn't exactly doing nothing, either. When you need it, it's extremely valuable. Maybe reframe your expectations. You buy insurance that costs you money out of pocket, don't you? This cash is insurance that your business keeps flowing smoothly when you need it. That is an enviable position for most businesses.
In the event of a business downturn, when money is harder to get, you'll have a leg up on your competition. And you can feel smug as hell that you didn't chase returns.
As to helocs being frozen, I brought this up on another thread and people refused to believe it. Given that the evidence is a mere Google search away, I thought the naysaying was ridiculous. It happened to thousands of homeowners, through no fault of their own.
I am assuming that you have other funds invested in equities. Just keep adding to them like a badass mustachian and you'll be fine.