#交易流动性

Old Yang has lived by the river for sixty years. He remembers when he was a child, the river water was clear enough to count the pebbles on the riverbed, and in the summer, there were always people swimming and fishing. Later, an upstream chemical plant was built, and the river water gradually turned black, the fish disappeared, and people stopped coming.

His son took him to live in the city, but Old Yang always thought about this river. Every time he returned, he would squat by the bank in a daze, as if he could still hear the laughter from the past.

This spring, Old Yang suddenly received a message from his son: "Dad, the chemical plant has closed, and the government is going to clean up the river!"

When he hurried back, excavators were clearing the silt, and workers were pouring purifying agents into the river. Old Yang squatted down and scooped up a handful of water—still murky, but sunlight shone through, and a small fry swam between his fingers.

He smiled, and murky tears splashed into the river.

What flows will eventually return.