<I wonder what the effect is on the money supply by cryptocurrency and whether that "cash", conjured out of thin air, is now fueling the stock market. Is it inflation if the new inflow of money is sequestered in equities?>

Jeff, you're a little late with that question. Like... 17 years late. The Federal Reserve has been inflating assets (stocks, bonds, real estate) since 2008 by pumping money they conjure out of thin air.

St. Louis Fed (FRED): Assets: Total Assets: Total Assets (Less Eliminations from Consolidation): Wednesday Level (WALCL) | FRED

More recently, the Shadow Banking System has been inflating asset prices using rehypothecation. Economists refer to a collateral multiplier, which is the measure of the reuse of collateral. Estimates have shown: the collateral multiplier for U.S. Treasury securities has fluctuated between six and nine times, meaning $1 of Treasury collateral can support $6 to $9 in new financing. For other collateral classes, the multiplier has been more stable at around three times.

Google: App 721e27c4c5cda2ac

This is an enormous amount of funny money which inflates all asset prices.

As for cryptocurrency...Based on recent market data, the total market cap of all cryptocurrencies is generally in the range of $3.7 to $3.9 trillion. For comparison, GDP is $30 trillion.
Since real dollars are taken out of the money system to pay for cryptocurrency this reduces the money available to buy stocks.

Wendy