So… Not quite how it works. The company gets an authorized number of shares which it can then issue out, or sell to shareholders.
If you own 100 shares out of the 1000 they are authorized, you own 10% of the company.
Now if they request and are authorized more shares (which is what happened here), your stake in the company is cut down. Let’s say they get authorized and issue another 1000 shares, bringing them to 2000 total shares. You now only own 5% of the company.
And with these new shares hitting the open market, prices will drop because now there is “more supply than demand” (it’s an easy way to think about it). In theory the whole thing will eventually even out, but that generally doesn’t happen here because the value of the company hasn’t changed.
This whole thing is different compared to a stock split, which affects the price and the number of stocks, but not your overall stake in it. If a company does a 2:1 split, your shares will double, but the price per share will be cut in half. 10 shares at $10 now becomes 20 shares at $5… Your stake is still at $100