By Rob Lenihan Crypto prices are coming down one day after Biden signed his executive order on cryptocurrencies. Well, that didn’t last long. Bitcoin and other digital currencies were sliding Thursday, one day after President Joe Biden signed his executive order on cryptocurrencies. Bitcoin was down 6.3% to $39,314 at last check, according to CoinGecko, while ethereum was off 4.7% to $2,605 and dogecoin slipped 4.1% to $0.116924. ‘A Good Signal to Serious People’ Among other things, Biden’s order directs Treasury and other departments to come up with policy recommendations “to address the impl…