teeter

- To balance unsteadily, rocking back and forth, almost ready to fall

... While on a hike, George saw that the boulder was teetering at the edge of the cliff, and that even slight push could make it crash into the valley below.
... After the company's treasurer was caught stealing, the company's stock plunged, and the financial state of the company was teetering, and no one knew if it would survive.