If you ever want to check your overall investment stats per planet, just click on Career then the Stats icon in the top-left. From there, you can scroll down and check our the following:
Cash on Hand: Your current cash amount on that respective planet/moon
Session Earnings: How much you've earned overall in that playing session (this will reset after resetting for Angel Investors)
Lifetime (insert planet/moon) Earnings: This is your total cash you've earned on the respective plant/moon
Total Resets: How many times you've reset your game to gain Angel Investors
Total Angel Investors: Your current amount of Angel Investors
Angels Sacrificed: How many Angel Investors you've sacrificed for Angel Investor Upgrades
Unlocks Earned: How many Unlocks have you earned altogether? You can see here.
One more thing; if you've completed a planet and opted out of reseting your stats, you can reset the planet through the Stats menu whenever you're ready to start your adventure over again!