I'm not so sure that the author currently has 10k in bonds. The pseudo-code for the purchasing backend might just look like

    totalReceived = totalReceived + transactionAmount
    if (totalReceived > 10000) {
        sendEmail()
        wait10weeks()
        refund(transactionAmount)
        totalReceived = totalReceived - transactionAmount
    } else {
        buybonds(transactionAmount)
    }

In which case, the author would have 20k locked up in the government and only $25 invested.

A horrible way to write a system of course but if the system takes 10 weeks to process a refund then it doesn't sound like the system is that great to begin with