If we assume for simplicity sake that the bills come in uniformly throughout the month, then the average heloc balance for the month becomes 191.5k per day.The problem is that you are getting a benefit on the (relatively) small 10k payment you made, and getting hurt on the massive 191.5k balance that stayed on the heloc the entire month at a higher interest rate versus a mortgage.Months vary in length, but are roughly 30.4 days on average. 

I live in Lake Tahoe which has seen a massive boom due to COVID.  

They don't want to hold stocks for two reasons, 1) many folks believe they're overvalued (rightfully or not) and 2) when you're retirement age it's not feasible to ride out a multi-year decline in stocks (aka it's too risky to have your retirement money there).OK, so we understand there's a massive number of folks that NEED yield (not just want like so many here on BP) and there are increasingly fewer places to get it.

[House Hacking] I want to start house hacking because using so little cash to control a 300k+ asset can provide massive returns.

Really helpful as I'm taking massive action!

This was a massive rehab.

This recent flip was my desperate attempt at taking massive action.

OK, we have a moratorium on our mortgages, but unless there is some relief for property owners on the back side there will be a massive foreclosure market.

In this scenario you get the benefits of early pay down but you aren't only paying massive interest upfront.

One of my favorite lines from Warren Buffet is, " Be fearful when others are greedy, and greedy when others are fearful."