You said:
NIO Stock Is Soaring, Tesla Continues to Fall
Since you did not provide a window of time over which the comparison was made, we have to guess it.
The comparison for 5 years ending today shows TSLA is down 27%, while NIO is down 66%.
Per a one-year comparison chart, TSLA is down 21% whicle NIO is down 61%.
The relative performance holds for the last 6 months, the last 3 months and the last month.
So, as usual, I have absolutely no idea what facts your post is based on.