What are the advantages and disadvantages of financial markets?

What are the advantages and disadvantages of financial markets?
The existence of financial markets allows for the ability of a company to raise funds for a new product, or for the ability of a partnership of individuals to raise funds to begin a new company. Financial markets provide the liquidity and the forum in which to trade either stocks and bonds or commodities. The existence of financial markets is part and parcel of a free market economy. And, in some cases, even highly regulated, or government owned companies, will allow for a sector of publicly owned companies to have their stocks and bonds bought and sold. Thus for example, a nation may own and operate the nation's defense industry, but allow for companies that supply parts for that industry to be publicly owned corporations who operate for profit.
The disadvantage of financial markets is if they are not operated honestly, or find ways to get around sound and legal methods of operation. Happily, such markets will not exist as "rogue" operations for too long. As individuals, news media and government regulatory bodies will find out about these types of problems and apply corrective measures.