Brokerage account 的那個投資銀行的證明,證明你可以每月取出三倍於mortgage monthly payment 的數目,而且brokerage account 的balance足夠取三年的。
即: 假定mortgage monthly payment is $1000, you will need a balance of $1000*3*36 months = $108,000 in the brokerage account. 這個Brokerage account 裏麵可以有SPY, QQQ, SPAXX,Tesla, Apple...等不同的股票證券基金或money market 上麵, 不必非要在SPAXX 上麵。