Elon Musk's warning about the risks of margin loans and market volatility could cause some investors to be more cautious, potentially impacting the demand for Tesla's stock. Additionally, ARK Invest's sale of Tesla stocks could be interpreted as a lack of confidence in the company's short-term performance, which could negatively affect the stock price. RBC Capital Markets' prediction of lower-than-expected Q2 deliveries could also lead to a decrease in investor confidence and a potential drop in the stock price.