>> Yes, assuming you have not early exercised. This sucks.
Would the stock's value today be based on the company's valuation at the most recent round of funding?
>> Yes, the 409A valuation, which is generally ~30% of the valuation you hear about on TechCrunch for Series B-C companies. Investors received preferred stock. You have common stock.
If the company goes on to raise more VC funding, would I be liable in future years for the 'capital gains' on this stock?
>> Only when you sell it. Same as public stocks -- if you buy Twitter stock, and sell it in 5 years after it's gone up 2x, you have to pay cap gains only once after you sell.
If the company went on to fail, would I be entitled to tax breaks for loss of stock?
>> Not sure. The rules around this are pretty complex. Ask a lawyer.
>>>> So, if the company hasn't raised funding since I was offered my options, would I have zero tax liability for exercising my vested options?
1 - the company has executed well and increased their value;
2 - to ratchet golden handcuffs tighter