Stocks are rallying and bonds and precious metals are tumbling after Pfizer and BioNTech this morning announced 90% effectiveness after the second dose of their Covid-19 vaccine candidate. The data is preliminary at this point, and is only from a very small sampling of a much larger study.Bitcoin (BTC-USD) has been active, initially rising to as high as $15.8K, but falling since, and now changing hands at $15.3K - still more than a double for 2020.Among the bull arguments for Bitcoin has been a somewhat dystopian future of never-ending, pandemic-related monetary and fiscal stimulus driving the value of traditional currencies to an ultimate resting place near zero.In other news, Jeff Gundlach recently weighed in on central bank moves to create digital currency. A product like that, says Gundlach, would give central banks the "necessary plumbing" to deliver money directly to citizens' bank accounts, opening "veritable floodgates" of liquidity and accelerating