You can imagine the price movement of each day as a "tug of war":

The bulls (bullish people) are on the left, wanting to push the price up.
Bears (people who are bearish) are on the right, wanting to pull the price down.
A K-line is a record of the results of the tug-of-war competition on that day.
1. Long upper shadow (sharp rise and fall)
Like a "meteor" or "lightning rod".
Today's price, originally ambitious, surged up (the lead-in part) quite well. But after reaching the high point, it was found that the pressure above was too great, with too many sellers. As a result, it couldn't hold steady and was slammed down all the way, and by the end of the trading session, it was almost back near the starting point.
For example:
You climbed a mountain and put in a lot of effort to reach the top, but a gust of wind blew you back to halfway up the mountain. During the exam, you started off answering questions very smoothly, thinking you could score 100 points, but then you got all the big questions wrong and ended up with only 70 points.
It tells you what information:
1. At a high position (after a long rise): This is a signal of "be careful." It indicates that there is enormous selling pressure above, the bulls are losing strength, and the price may fall. Just like the wind when climbing a mountain, it tells you that the wind at the top is too strong, don't go up.
2. At a low point or halfway up the mountain: it may just go up to "test" a bit, to see if there are still sellers above. If it rises again the next day, then nothing is wrong.
The core is just one sentence: There is pressure above, and it can't go up!
2. Long lower shadow (bottom fishing rebound)
Like a "hammer" or "nail".
Plain explanation:
The price today is quite miserable, it kept dropping after the opening, falling drastically. However, after reaching a certain low point, it was found that there were buyers ready below, and the buying pressure was very fierce, resulting in a strong recovery, and finally at the close, it ended at a relatively high position of the day.
It's like:
When you dive, you plunge into the water, but there is a springboard at the bottom that bounces you back to the surface.
You made a big mistake and were scolded by the teacher (price movement), but in the end, you admitted your mistake with a good attitude, and the teacher forgave you (recovered).
It tells you what information:
1. At low levels (after a long decline): This is a signal of "hope." It indicates that there is strong support below, and someone thinks this price is cheap, buying frantically, which may lead to a rebound as the price hits the bottom. Like a diving springboard, it tells you that it has reached the bottom and cannot drop further.
2. At a high position or halfway up the mountain: It may just be a "wash-out" to scare off the weak hands, and then the main force will pull it back up.
The core message is: there is support below, it won't drop!
How to remember? A super simple metaphor
Like a person jumping to touch a height, but didn't reach it and fell to the ground.
Like a person falling into a pit, but the bottom of the pit has a sponge that bounces him back up.
The most important reminder
Look at these two signals, position is key!
The "lightning rod" (long lead) that appears at the top of the mountain is much more dangerous than the one that appears halfway up.
The "hammer" (long lower shadow) that appears in the valley is much more reliable than the one that appears on the hillside.
Never rush in to buy just because you see a long lower wick; first, check whether it is at a high or low position. #GateFun社区上线