This is not the case in gambling or commodities markets; for me to win, someone else has to lose.
Call whatever you do 'investing' if it makes you happy, but as I said before, you can replicate financial 'investments' with spread-betting 'bets' and you will make the same gains and losses.
Someone wants money today, and is willing to give up more money tomorrow for that money today.
If it weren't for big stock IPOs, Angel Investors and Venture Capitalists wouldn't invest into startups. Not everyone is looking to hold stock for 20 or 30 years... especially Angel Investors who are addicted to helping out small startups.
Buying stock from an Angel Investor who is IPOing allows the Angel Investor to invest into another small company, and transfers the ownership of a (used to be) startup, to your control. IE: Facebook and Twitter. Angel Investors would rather own a smaller, more volatile company... while the typical investor would rather own the bigger, more stable companies for their retirement.
Its not necessarily about "winning" and "losing". If an early Facebook investor liquidates his $$$ in Facebook, it allows him to help out another company. He doesn't care how Facebook does in the future, because he's far more interested in helping startups.
Again, its win/win for everyone. Everyone benefits when the Venture Capitalists sell off their stocks to the Stock Market.
No. If you sell shares to pay for living expenses you do not lose. If you dilute your shares to raise capital to make your remaining shares worth more you do not lose.