This guy is definitely saying that Bitcoin money supply (market cap) should be compared with "monetary base" (MB or M0) ... but it's not clear that the CIA usage of M1 for "stock of narrow money" is used widely anyway.
http://www.dgcmagazine.com/bitcoin-money-supply-and-money-creation/What should not be done is to compare the Bitcoin monetary base to the M1 money supply of fiat currencies. As long as there are no figures on the total outstanding Bitcoin loan volume available, we wont know what Bitcoin M1 is. We would need to sum up mined Bitcoins and outstanding Bitcoin loan volume in order to get Bitcoin M1. As we have seen on the Euro zone example, the larger part of M1 is created from lending. A comparison of the Bitcoin monetary base with M1 of other currencies would try to compare two incomparable figures.