Can I order RTB from overseas? February 28, 2020 02:49 Updated Yes, as long as you have a FirstMetroSec account. Related articles Can I order RTB anytime? How to participate in corporate bond issuances? Are RTBs risky? Retail Treasury Bonds Due 2028 (RTB 28) FAQs For RTB purchase, I already funded my account but the prompt still says not enough buying power.