Actually he could. Vanguard would easily absorb it. Vanguard has about 4 trillion dollars of assets under management. $40B corresponds to about 1% of it, about a single day's stock market wiggle.
Are you getting confused because the scientific notation would be 6 x 10^10? But that's not how people count "figures." If you have a 6 figure salary, your salary is $100,000 to $999,999, not $1,000,000 to $9,999,999.
These allow larger trades to be done without affecting the market price.