The U.S Benchmark sets the oil prices depending on the supply and demand. Gas and oil prices are rising and falling so much because of the number of investors, and the demand among the American people.
The U.S. Benchmark sets the oil prices according to the supply and demand for oil, in a little town call Cushing, Oklahoma. The demand for oil this year had plunged twenty [Express numbers higher than nine in digits (when not the first word in the sentence)] four percent. In the past four months the demand and supplies for oil has shot up one hundred forty [Express numbers higher than nine in digits (when not the first word in the sentence)] two percent because now [Clearer writing suggestion: Unless you are making a philosophical statement (Now is the time to improve myself) or mean "as of the present time" (and the business is now known as Ajax Corp.), consider removing "now"--since this is being read after the time you wrote it, "now" is in the past] it is getting ["getting" is informal English and can mean many things; in academic writing, use forms of "arrive at," "can," "could", "grows," "is able to," etc.] colder and [Possible error: place comma before "and" if what follows is an independent clause (could be a sentence by itself)] some people need it to heat their homes. This meaning the price of oil has gone up again after a small break from the high prices during the warmer months. Which everyone knows, prices are always higher in the winter.
Oil companies make their money as long as there are investors investing in their product. The more investors the oil companies have the richer they become. It is ["It is" is an awkward phrase if "it" is not clearly a thing] not illegal to invest in oil futures. Matters of fact, investors are back bigger than ever after regulations scared them away last year. People invest thinking it is a way to make a quick buck, which it is but the stock market is shaky and could plummet and we [Word choice. In academic writing, second person (you and your) should be replaced with a third person pronoun (he, she, it, one, and they). ] [Eliminate second person (you, your) in academic documents and avoid addressing the reader directly. Use third-person pronouns (he, she, it, they)--check the rest of the composition] could lose [Check spelling: "loss" is a noun (The loss was minor); "lose" is a verb (The company will lose more employees)] all of our [Do not use second person in academic writing.] [second person] money with it.
The demand for gas was down ten [Express numbers higher than nine in digits (when not the first word in the sentence)] percent in the past year, due to conservative drivers and unemployed people. People were conserving their gas by doing all their errands at one-time,[A hyphen is required between these two words. Place a hyphen between two words that act as an adjective. No space appears before or after the hyphen. Example – a well-known play.] and cutting back on unnecessary traveling that they would normally be doing if gas prices were not so high. OPEC means Organization of the Petroleum Exporting Countries. They are an intergovernmental organization made up of thirteen [Express numbers higher than nine in digits (when not the first word in the sentence)] oil producing nations. OPEC coordinates A petroleum policy of other oil producing countries and tries to stabilize oil markets to secure Economic and supply of petroleum to consumers, and to make sure that those who are investing in the petroleum get [Avoid forms of "get"] their fair share. OPEC is keeping their rates of production fixed so they have no need to decrease their prices. Prices are so high that businesses that rely on gas for deliveries won’t be able to stay in business, which means loss of jobs. With loss of jobs people don’t have to fill up their gas tanks as much because they do not have to go back [...