I've read a book and it said there is a job who buys and sell stocks to keep inventory for the traders. "market maker"??. like doing the trade of stocks at a market. to keep an inventory of stocks and controlling price. How do you become one? What is the requirement? How much salaries do they earn? I checked in google but didn't show me anything so I was wondering if such job exist or not.
The fellow named Christian below is slightly incorrect. There is a job title called market maker. Said people have to have a starting capital of over $1 million depending on the stock. But they are in charge of smoothing out the spread on major stocks (1 person only 'makes' 1 stock). They make their money through arbitrage. I suggest looking up a site that has the job definition and then searching through its sources. Ie. wikipedia if they have an entry. Don't trust what people say until you see verified sources (including me lol). A recent statistic from a book I'm reading is that surprisingly, the number of market maker's has markedly increased since 2000, yet the average profit made has increased by 30%. Go figure. To become one, I suggest getting a crap load of education, credentials, and experience, oh, and over $1 million to start with :D
A market maker is different than what you are describing. What you are describing is a broker-dealer. Broker-dealers are sometimes market makers, but market makers don't have to be broker-dealers.
Broker-dealer has two components ("broker", and "dealer"). A broker-dealer is licensed by the government to do both. A broker-dealer is acting as a "broker" when he acts as a middle-man to help a person who would like to own a stock to buy one. He may charge a commission to find a seller and deliver the stock to the new owner.
The broker-dealer acts as a "dealer" when he does what you are saying above, he owns an inventory of securities that he can deal out to clients at whatever price he feels like selling them for.
If a dealer has most all of the public shares available for some company then he pretty much has a monopoly and can sell those stocks to anyone for whatever price he darn well pleases. (as long as he can find a buyer). In this way, the dealer can sort of control the price of the issue.
Investment banks are usually involved in dealing and market-making. An investment bank is not like a normal deposit bank that you would think of like wells fargo or bank of america. An investment bank just helps sell stocks and bonds. They are usually so big that they will "underwrite" an entire issue of stocks or bonds. What they do here is they purchase all of the securities that a company is wishing to sell at the underwriting price, then mark up the price to sell to the general public, reaping huge profits.
I don't know a lot about working as a broker-dealer or investment banker. Look the terms up in google or on hotjobs. There might be some more info there.
In academic discussion, we refer to a market maker as someone who acts as one. So, if you buy when the stock goes down, and sell when it goes up, trying to make money off of the bid-ask spread, you have become a market maker.
Most of the people who do this work at a broker dealer, usually at a investment bank.