When it comes to investment products, the darling of this inflationary moment has been the unassuming high-interest savings account (HISA) fund. With more than $29 billion in assets, much of that accumulated since interest rates started rising last year, HISA funds have dominated monthly inflow stats. They’ve also caught regulators’ attention. This week, following a review announced in May, OSFI said it’s raising liquidity requirements for the products. As of Jan. 31, banks will have to classify deposits from HISA ETFs as unsecured wholesale funding with 100% run-off. Here’s how the new rules could affect the yield offered on the products, and how the fund industry is adapting.