As already noted [4], yesterday one after another FX broker scrambled to disconnected the Russian currency from the system due to "western banks stopping quoting pricing" and as a result of epic volatility (and as everyone knows, brokers prefer to only trade those pairs where they know with near certainty they can pick 1 pip or so from every trade which is why they prefer stability and orderly markets). However, in the aftermath of today's announcement that the Russia finance ministry will join the central bank in selling reserves, the RUB has found a bid. And sure enough, here come the FX brokers barging back, advising that Ruble trading is set to resume this afternoon.
[5]
So enjoy the return of the USDRUB pair... at least until another burst of buying (i.e., RUB shorting) on any news out of Russian - or for whatever reason - sends risk assets, and crude, tumbling all over again at which point the Ruble will once again be halted from retail participation.
Rinse. Repeat.