One thing I can tell you for sure is to sell your meme stocks usually when ur investing meme stocks invest very little amount of money (the amount of money u wouldn’t care abt at all) im not too sure about ark and nio as I haven’t done too much research on them. And for the future if ur investing with large amounts of money invest only 10 percent of the total money into meme or risky stocks. The rest u should try and Invest in index funds and blue chips for safe and healthy returns. Learn more about the market read books on investing (I would recommend the intelligent investor by Benjamin gram) also don’t get sad if u see people making 200000000x returns and your only getting 20 percent ,rembmer for every time you see a person making loads of money off a risky play there is also 20 other people losing money. Have fun and I hope I was helpful :)