You have heard about black money, let's know something about 'Grey Money'.
Grey Money is related from tax evasion. For example, gray money includes illicit deduction or funds hidden in an offshore bank.
The Grey market, also referred to as the parallel market, is a market where a product is bought and sold outside of the manufacturer's authorized trading channel.
The grey market is where the unofficial trading of a company's shares, usually before they are issued in an initial public offering (IPO), happens. The distribution channels involved in the grey market are legal but are not provided by the original owner.
Grey Markets VS Black Markets
Grey markets should not be confused with black markets since they have a very distinct difference. Grey markets are imported goods sold purchased at a less expensive price and sold for a higher price. The importation of prohibited and illegal goods like firearms and drugs do not fall under the grey markets.
These items are considered to be part of the black market. Goods under the black market are typically products that are smuggled into particular countries to avoid import matters.
Source: AK (Q&T)