Grand Theft Auto 5 gamers can perform assassinations missions and work the stock market to get big sums of money quickly.

Before the beginning of the mission given to you by Lester, make all three characters invest in specific stocks depending on the mission. For the Hotel Assassination, make all three characters invest in BetaPharmaceuticals (BAWSAQ). Invest in Debonaire Cigarettes (LCN) for the Multi Target Assassination.

In the Vice Assassination, invest in Fruit (BAWSAQ). For the Construction Assassination, invest in GoldCoast (LCN). Do not wait until the mission starts, since this will only limit your investment to Franklin.

After the mission is completed, go to a safehouse and sleep around three different times, which will pass the time by 18 hours. After you've awoken, there should be a huge return on your stocks. Sell all of them and collect your money earned.

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Another way to take advantage of the stock market is by assassinating a rival company's leader. This will automatically increase the stock of the company you've invested in. Remember to make sure that all three of your characters have invested in the same stock.

A less time-consuming way of making money fast is by robbing various businesses. To hold up a store and rob them of their money, all you need to do is walk in and point a gun at the clerk. The clerk then puts all of the cash into a bag which you can then escape with.

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You can also steal a bank van and blow its doors off in the back, which allows you to steal all the money in the van.

For more ways of getting money through less legal means in Grand Theft Auto 5, watch the video below: