Originally, the most important U.S. stocks were traded on the New York Stock Exchange. A trader would contact a stockbroker, who would relay the order to a specialist on the floor of the NYSE. These specialists would each make markets in only a handful of stocks. The specialist would match the purchaser with another broker's seller; write up physical tickets that, once processed, would effectively transfer the stock; and relay the information back to both brokers. Before 1975, brokerage commissions were fixed at 1% of the amount of the trade, i.e. to purchase $10,000 worth of stock cost the buyer $100 in commissions and same 1% to sell. Meaning that to profit trades had to make over 2 % to make any real gain.
Due to the increased leverage and quick returns, day trading can be extremely profitable. The downside is that if done incorrectly, it can also be extremely unprofitable. Due to the high volatility of day trading, some people have labeled Day Traders as gamblers or adrenaline junkies. However, many people make a very consistent and comfortable living from day trading. Some even make millions of dollars each year.
Rebate trading is an equity trading style that uses ECN rebates as a primary source of profit and revenue. Most ECNs charge commissions to customers who want to have their orders filled immediately at the best prices available, but the ECNs pay commissions to buyers or sellers who "add liquidity" by placing limit orders that create "market-making" in a security. Rebate traders seek to make money from these rebates and will usually maximize their returns by trading low priced, high volume stocks. This enables them to trade more shares and contribute more liquidity with a set amount of capital, while limiting the risk that they will not be able to exit a position in the stock.[16]

A day trader often closes all trades before the end of the trading day, so not to hold open positions overnight. A day traders' effectiveness may be limited by the bid-ask spread, trading commissions, as well as expenses for real-time news feeds and analytics software. Successful day trading requires extensive knowledge and experience. Day traders employ a variety of methods to make trading decisions. Some traders employ computer trading models that use technical analysis to calculate favorable probabilities, while some trade on their instinct.
Scalpers need to be disciplined and need to stick to their trading regimen very closely. Any decision that needs to be made should be done so with certainty. But scalpers should also be very flexible, because market conditions are very fluid and if a trade isn't going as expected, they'll need to fix the situation as quickly as possible without incurring too much of a loss. 
The bid–ask spread is two sides of the same coin. The spread can be viewed as trading bonuses or costs according to different parties and different strategies. On one hand, traders who do NOT wish to queue their order, instead paying the market price, pay the spreads (costs). On the other hand, traders who wish to queue and wait for execution receive the spreads (bonuses). Some day trading strategies attempt to capture the spread as additional, or even the only, profits for successful trades.[18]
In March 2000, this bubble burst, and a large number of less-experienced day traders began to lose money as fast, or faster, than they had made during the buying frenzy. The NASDAQ crashed from 5000 back to 1200; many of the less-experienced traders went broke, although obviously it was possible to have made a fortune during that time by short selling or playing on volatility.[9][10]

This is usually reserved for traders working for larger institutions or those who manage large amounts of money. The dealing desk provides these traders with instantaneous order executions, which are particularly important when sharp price movements occur. For example, when an acquisition is announced, day traders looking at merger arbitrage can place their orders before the rest of the market is able to take advantage of the price differential.
Disclaimer: Trading carries a high level of risk, and may not be suitable for all investors. Before deciding to invest you should carefully consider your investment objectives, level of experience, and risk appetite. The possibility exists that you could sustain a loss of some or all of your initial investment and therefore you should not invest money that you cannot afford to lose. You should be aware of all the risks associated with foreign exchange trading, and seek advice from an independent financial advisor if you have any doubts.
The following are several basic trading strategies by which day traders attempt to make profits. In addition, some day traders also use contrarian investing strategies (more commonly seen in algorithmic trading) to trade specifically against irrational behavior from day traders using the approaches below. It is important for a trader to remain flexible and adjust techniques to match changing market conditions.[11]
Day trading is normally done by using trading strategies to capitalise on small price movements in high-liquidity stocks or currencies. The purpose of DayTrading.com is to give you an overview of day trading basics and what it takes for you to make it as a day trader. From scalping a few pips profit in minutes on a forex trade, to trading news events on stocks or indices – we explain how.
Trend Trading is a strategy where it is believed that a stock that is rising will continue to rise, or a stock that is falling will continue to fall. You enter the trade in the direction of the trend and exit once the price breaks this trend. Trend trading usually incorporates the use of trend and support/resistance lines. Click here for more information on Trend Trading.
Traditional investing – Traditional investing is a longer game and looks to put money in popular assets such as stocks, bonds, and real estate for long-term value appreciation. Realistic investment returns over a whole year are in the 5-7% range. Unless you are already rich and can invest millions, traditional investing returns too little to make much of a difference on a daily basis. However, the intelligent trader will also invest long-term.
The intraday trading strategy to be used also depends upon the traders’ personal trading styles, along with being dependent on the market conditions. Some traders are very active and do many trades a day, with large position sizes, catching even the small price movements; while there are others who trade only on specific news events or only on tendencies that they have well researched.

Now, it’s very easy to maximize the daily profit using Intraday Trading Techniques / Formula in NSE India. Stock market fluctuations every time gives trader surprises and therefore trader should be ready to accept and challenge the unexpected. With the proper Intraday Trading Tricks and knowledge, the trader can have the road to intraday trading success in the long run.  As the name suggests, intraday trading is a type of trading when the shares are bought and sold on the same day.  The risk associated with Intraday trading is very high then another trading. But, if the trader plays safely with the right trading rules, he/ she can have success in Intraday.
Many professional money managers and financial advisors shy away from day trading arguing that, in most cases, the reward does not justify the risk. Conversely, those who do day trade insist there is profit to be made. Day trading profitably is possible, but the success rate is inherently lower because of the complexity and necessary risk of day trading in conjunction with the related scams. Moreover, economists and financial practitioners alike argue that over long time periods, active trading strategies tend to underperform a more basic passive index strategy, especially after fees and taxes are taken into account.