The PSARs under the closes, which act as support, are summed separately and shown in green. The PSARs over the closes (acting as resistance) are summed separately and shown in red.
The result is an indicator which can be interpreted somewhat like the (but keep in mind that PSAR is a lagging indicator unlike the which is a leading indicator). By interpreting this correctly you can - SOMETIMES - predict the short-term turns of the entire crypto market.
Many traders use the prices shown by PSAR ( ) to set stop loss prices and/or to take profit and reverse their positions. This is why, on reversal of the PSARs (= when one of the red or green values becomes visibly larger than the other), a strong turning of the market can, sometimes, occur.