Parabolic SAR indicator represents the turning point at which the price should be bought or sold. This kind of technical analysis tool is quite similar to the moving average principle, which is an analysis tool that pays equal attention to price and time. Since the points that make up the line move in an arc, it is called a parabolic turn.
The calculation formula of SAR is divided into ascending and descending formulas, namely:
Ascending SAR2 = SAR1 + AF (H1－SAR1)
Descending SAR2 = SAR1 + AF (L1－SAR1)
Where: SAR1 ── Yesterday's SAR value, the initial value of the rising type is the lowest price in the near future, and the initial value of the falling type is the highest price in the near future.
H1 ── The current highest price. L1 ── The current lowest price. AF ── Wilt’s acceleration factor, with a base value of 0.02. When the price reaches a new high (rising) or new low (declining), it will increase by a multiple of 1, 2, 3... until 0.2, that is AF = 0.02～0.2.
It can be seen from the formula that when the initial value of SAR1 is taken as the recent lowest price, that is, when the market is regarded as rising, the condition of the current highest price H1 > SAR1 must be met. Once H1
3.1 The parabolic SAR indicator is the mid-termindicator of the strong market. In the Shanghai and Shenzhen stock markets, it is more suitable for investing in stocks with good fundamentals, such as investing in high-quality stocks and technology stocks. It is more suitable for medium-sized funds (3 million to 20 million). It is not suitable for use in the second half of the year.
3.2 When the stock price rises, the red circle of the SAR is located below the stock price. When the closing price of the stock drops below the SAR, it should be sold immediately. 
3.3 When the stock price falls, the green circle of SAR is located above the stock price. When the closing price breaks the SAR upward, it can be bought back.
3.4 When the stock price is above the red circle of SAR, if CR is foreseen for a signal that four lines gather at one point, it is a rare short-term main acceleration signal, and attention should be paid to it.
3.5 When the stock price is below the green curve of the SAR, it indicates that the current market is bear market and should stay on the sidelines. Especially in the process of falling, although sometimes the green circle turns over the red circle phenomenon, if only 3 or less red circles appear, it cannot read as a single buy signal and must be considered with other technical indicators.
3.6 SAR is more accurate in gauging the stocks with larger trading volume.
4.1 The operation is simple, the buying and selling point is clear, and the trades can be carried out when the buying and selling signals appear. It is especially suitable for small and medium investors who , lack of investment experience, and lack of trading skills;
4.2 "Bull stocks" suitable for continuous pull will not be easily shaken and washed by the main force;
4.3 "Bear stocks" suitable for continuous declines will not be deceived by a rebound on the way down;
4.4 Suitable for medium and short-term band operation;
4.5 Although long-term use of the SAR indicator cannot buy the lowest price or sell the highest price, it can avoid the danger of long-term lock-in and at the same time avoid missing the bull stock market.