Microsoft aren’t likely to do it, but if a public company does raise money by issuing new shares they share price shouldn’t change (in theory) If they price the shares higher than the market price no one would buy them
in my example above say the £1,000,000 company raises £500,000 by selling 50,000 new shares at £10
The company is now worth £1,500,000. The share price is the same but there are now 150,000 shares in circulation.
It’s different with a non public company such as those on Crowdcube, as here is no price discovery by supply and demand, so they would decide on a valuation and share price, which would hopefully be higher than the last raise (but that doesn’t always happen)
They need to account for growth of the company and make as much as they can for the amount of equity they are offering, but price it at a price that’s attractive to investors, which is a bit of a balancing act.