Nothing on paper says "You own 50% of the company".
The company starts up, it has 100 shares, you get 50. If you calculate it, you own 50%.
Later on the company needs to raise cash, so it issues another 100 shares. Company now has a ton of cash in the bank. Total shares outstanding is 200. Now you own 25%.
The company starts up, it has 100 shares, you get 50. If you calculate it, you own 50%.
Later on the company needs to raise cash, so it issues another 100 shares. Company now has a ton of cash in the bank. Total shares outstanding is 200. Now you own 25%.