Retail day traders are competing with professionals. Pros know the tricks and traps. They have expensive trading technology, data subscriptions and personal connections. They’re perfectly outfitted to succeed, and even then they often fail. Among these pros are high-frequency traders, who are looking to skim pennies or fractions of pennies — the day trader’s profit — off every trade. It’s a crowded field, and the pros love to have inexperienced investors join the fray. That helps them profit.
Retail investors are prone to psychological biases that make day trading difficult. They tend to sell winners too early and hold losers too long, what some call “picking the flowers and watering the weeds.” That’s easy to do when you get a shot of adrenaline for closing out a profitable trade. Investors engage in myopic loss aversion, which renders them too afraid to buy when a stock declines because they fear it might fall further.
By holding overnight, the swing trader incurs the unpredictability of overnight risk such as gaps up or down against the position. By taking on the overnight risk, swing trades are usually done with a smaller position size compared to day trading (assuming the two traders have similarly sized accounts). Day traders typically utilize larger position sizes and may use day trading margin of 25%.
The first type of scalping is referred to as "market making," whereby a scalper tries to capitalize on the spread by simultaneously posting a bid and an offer for a specific stock. Obviously, this strategy can succeed only on mostly immobile stocks that trade big volumes without any real price changes. This kind of scalping is immensely hard to do successfully, as a trader must compete with market makers for the shares on both bids and offers. Also, the profit is so small that any stock movement against the trader's position warrants a loss exceeding his or her original profit target.
When you start day trading you’ll have a host of difficult decisions to make. Should you be using Robinhood? What about day trading on Coinbase? Do you have the right desk setup? Where can you find an excel template? How do you set up a watch list? The meaning of all these questions and much more is explained in detail across the comprehensive pages on this website.
There are a variety of methodologies to capitalize on market swings. Some traders prefer to trade after the market has confirmed a change of direction and trade with the developing momentum. Others may choose to enter the market on the long side after the market has dropped to the lower band of its price channel—in other words, buying short-term weakness and selling short-term strength. Both approaches can be profitable if implemented with skill and discipline over time.
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.
Sincere interviewed professional day trader John Kurisko, Sincere states, Kurisko believes that some of the reversals can be blamed on traders using high-speed computers with black-box algorithms scalping for pennies. “That’s one of the reasons many traders get frustrated with the market. The timing is not like it used to be, and many of the old rules don’t work like before.” 
Take profits near the upper channel line. If the market is strong, you can wait for the channel line to be hit. If it's weak, grab your first profit while it's still there. What if a strong swing overshoots the channel line? An experienced trader may shift his tactics and hold a little longer, perhaps until the day when the market fails to make a new high. A beginning trader is better advised to take profits after the channel line has been hit as it's important to learn to take profits in accordance with one's trading plan.
Finally, keep in mind that if trading on margin—which means you're borrowing your investment funds from a brokerage firm (and bear in mind that margin requirements for day trading are high)—you're far more vulnerable to sharp price movements. Margin helps to amplify the trading results not just of profits, but of losses as well if a trade goes against you. Therefore, using stop losses is crucial when day trading on margin.
But this description of swing trading is a simplification. In reality, swing trading sits in the middle of the continuum between day trading to trend trading. A day trader will hold a stock anywhere from a few seconds to a few hours but never more than a day; a trend trader examines the long-term fundamental trends of a stock or index and may hold the stock for a few weeks or months. Swing traders hold a particular stock for a period of time, generally a few days to two or three weeks, which is between those extremes, and they will trade the stock on the basis of its intra-week or intra-month oscillations between optimism and pessimism.
Define and write down the conditions under which you'll enter a position. "Buy during uptrend" isn't specific enough. Something like this is much more specific and also testable: "Buy when price breaks above the upper trendline of a triangle pattern, where the triangle was preceded by an uptrend (at least one higher swing high and higher swing low before the triangle formed) on the two-minute chart in the first two hours of the trading day."