Actually technically thats not right, since post IPO valuation includes dilution of existing shares. $46-51 million includes the raised $5-10 million. So valuation before dilution is $41 million
August raise is calculated at $5 million valuation + $1.2 million raise = $6.2 million valuation after raise = 41/ 6.2 = 6.6x
October raise is $18 million + $2.5 million = $20.5 million = 41/20.5 = 2x
Still massive gains but not as high as you originally though, though comes with the risk thats why the gains are higher. Its only great when you win, but you'll also have to consider how many other investments that don't make it and to justify the risk they have to give a high reward. By no means do I think the valuation is worth it given no revenues and no ideal future prospects yet, though markets are not rational and think about the big possibilities that could happen.