As ASPA is not DTC eligible, the brokerage firms representing the seller has to physically deliver the cert to the buyers brokerage. The below links are from the first page googling Non DTC eligible securities https://ammeoinvestorblog.wordpress.com/2012/10/29/what-are-non-dtc-eligible-stocks-and-why-u-should-avoid-them/ https://www.mbtrading.com/f/NonDTCC_EligibleSecurities.pdf https://www.tradestation.com/site-wide-items/disclaimers/legal/disclosures/otcbb-disclosure https://www.firstrade.com/content/en-us/customerservice/faqs/illiquidfees/