If you read FY 2018 10k year end
Tauriga makes it abundantly clear that it values the warrants at $0 on the balance sheet
The company takes the most conservative possible approach. There is a paragraph on this in that 10k
So suffice it to say, the vistagen warrants will almost certainly be valued at $0
However they certainly are worth more than $0. Whether they currently are worth 30,40,50,60,70,80 cents etc etc. it is more than $0
Tauriga has made a decision to be ultra conservative about this stuff. No hedge fund in the world would value these 5 year warrants - realtively close to the strike price with 52 months left (has been over $1.50 many times since December 2017)