By what pathway do you believe it is possible to start a day with money in Vanguard, end the day with money in Bank of America, and hold ~$1 million in Bitcoin for some portion of the day.

Wiring a million dollars from Vanguard to BoA is a routine transaction, despite the degree of surprise that causes some geeks. More interesting commerce happens every day.

The Bitcoin transaction you have outlined, though, is not a routine transaction. I'd go further than that: it is impossible.

Well 45 min to 1050 min actually https://blockchain.info/charts/avg-confirmation-time