So far upstox has not given any explanation on as to what the hell happened that lead to the downtime yesterday.
So I assume that these people must have made big money yesterday by locking customers out of their accounts and then trading in their own account with customer's funds.
I keep, what is for me, a significant amount of cash in my upstox account for trading. With what happened yesterday, upstox has lost my trust. Time to find a new broker.