What happens to my money if StashAway winds down? Where is the asset kept?

Your funds are completely separate from StashAway's finances. 

Your money will always be segregated from StashAway's finances, and your assets will always be held in large institutions. Your cash deposits are temporarily held in a Trust Account at Citibank N.A. Hong Kong branch, where your money will be converted from HKD into USD (if you deposit in HKD) and transfers it to our broker (Saxo Capital Markets Pte Ltd) in Singapore to purchase the ETFs on your behalf.

Saxo keeps your portfolio at a segregated Trust Account at Citibank N.A. Singapore branch. Your funds are unmingled with the company.