As you progress through the game, you'll be able to spend Cash and Angel Investors to upgrade your Investments. Whether it's a profit multiplier or Angel Investor effectiveness boost, these will be essential for your capitalist success.
These can be accessed through the "Upgrades" section on the Menu. From there, you can choose from Cash or Angel Investor funded Upgrades.
One important note in regards to Angel Investor funded upgrades; once you spend your Angel Investors on an upgrade, they are gone forever. When it comes to AI Upgrades, we usually recommend spending only 10% of current total, until you are comfortable with assessing whether or not it's a worthwhile upgrade. The game will actually prompt you if you attempt to purchase an Upgrade outside of these perimeters.
As you progress through AdVenture Capitalist, more aggressive Angel Investor Upgrade purchasing strategy can be used to quickly boost your profits. However, using the 10% rule is a safe way of keeping your Angel Investor totals in check, without negatively affecting your profits.