Have you seen trading volume or total amount of "asks" altquick? There's also other place to buy/sell tBTC which doesn't disclose it's volume or available supply.
Speculation on future value may be the reason why testnet4 is already plagued by ASIC miners:
update it seems like somebody is running an asic on the testnet4... hashrate is 425 Th, so my 22Mh is < 1/19.000.000 of the current network hashrate... On average, i'd hit one block every >300 years. I just hope this asic-miner turns off his asic from time to time to give the cpuminers a chance...
