The approval of the compliance plan by Nasdaq is a significant positive development for NLS Pharmaceutics. It suggests that the company is making strides in addressing the issues that put its listing at risk. This news is likely to be viewed positively by investors, as it reduces the uncertainty surrounding the company's future on the stock market. The direct impact on the stock price should be positive in the short term, as it reassures investors of the company's efforts to meet Nasdaq's requirements.