They don’t stay in one place. The winds up there are light and variable and like hot air balloons down low they go up or down to control their flight path. My guess is they are all flying big circles up there.
I saw one while flying over Mississippi and it looked to be very high. It looked like a small white ball, about 5 mils in diameter. ATC said it was above the Class A. Perhaps Loon just floats downwind?