HSBC (HSBC) is said to prohibit its customers from buying shares of Coinbase (COIN) as it sticks to a policy of avoiding virtual currencies.The news comes after a report that was circulating earlier this week that that the bank banned customers on its online trading platform from buying shares of MicroStrategy (MSTR)."HSBC has no appetite for direct exposure to virtual currencies and limited appetite to facilitate products or securities that derive their value from virtual currencies," HSBC told publication Coindesk in a response to a question on Coindesk. "This is not a new policy.”Coinbase shares are largely unchanged in its second trading , one day after the cryptocurrency firm went public via a hot Nasdaq direct listing.