penny stock may vary but the Securities exchange commission (SEC) classifies penny stocks as companies traded under 5 dollars and many of them, if maintained above 1 dollar are still traded on the NASDAQ or the NYSE, the more regulated stock exchanges.
The more money you have in circulation the less its worth would be and that’s a problem.
For example if a massive inflation takes place and an average person, David has a million dollars but that million dollars actually worth is only to buy an apple. Then in this case the worth of a million dollar has gone down. The loss of purchasing power at a time is called inflation and when inflation gets out of hand money becomes worthless.