I know nothing about margin trading but wonder if this email from Schwab, which holds my TSLA, is worthwhile? I've never been asked to loan out my shares but probably never owned anything worth sharing before concentrating on TSLA.
Earn income for lending securities
Learn about Schwab's Securities Lending Fully Paid (SLFP) program, which may allow you to earn monthly income for lending securities to Schwab that are in high demand by other investors. Your account currently holds securities that may qualify for the SLFP program.
Please note that income paid on a loaned security can fluctuate with changes in demand in the securities lending market.
I was in Fidelity's equivalent program for a few years. At one point, I was being paid 14% to lend out my shares, with most months more like 5 to 8%.
I dropped out when the shares became easy to borrow and were all returned (or might get lent out for <1%).
I found it to be an entirely reasonable way to raise a bit of income from the shares I was going to hold regardless. Then the rate became too low and I haven't bothered researching the new rates. My perception is that TSLA is still cheap to short, thus lending the shares is barely better than US treasuries.