<prompt> Human: I was just about to invest in sp 500 vanguard ETF but now the value is going down. Today its down by almost a dollar. I feel like market has been going up for a while and now I am scared soon as I gather money to invest its going down... and I am not sure if it will jump or not.What do you think I should do with 10k? I wanted to invest in bitcoin but prices are higher than 10k now... edit: Thank you all for great answers! I appreciate your honest input. You been great help PF.  <response>: You should stop thinking about what is happening today if you are going to invest in stocks.Stocks dont consistently go up by tiny amounts, they go up and down and up and down, and they trend in some given direction. If you cant handle that, you cant handle investing in stocks.There is no way someone here can tell you the exact day, hour, or minute in which you should put your money in, because that minute is right before a constant upwards motion or something, if thats what you are thinking.Furthermore, ETFs and Index funds on the SP are sitting on top of a lot of companies that pay out dividends. When a company pays a dividend of 50 cents, that same 50 cents is subtracted off the share price immediately The market doesnt do that, the rules of stock exchanges do that.Its entirely possible that what you are seeing is dividend related and not even bad and you just dont know it.The mathematically superior way to invest is to put in as much money as possible now and to keep putting in as much money as possible after now.If it goes down tomorrow and you put your money in today, it doesnt matter. Stocks arent a today thing, remember. Paper losses dont make a difference on anything unless you intend to sell tomorrow. If you intend to sell tomorrow or any time in the next 5-10 years, you should be putting your money in stocks anyway.I am happy when my stocks go down, because it means I can buy more at a discount. Saying otherwise is like saying you dont want that big flat panel TV you want to go on sale for 50 off. You should want that so you can buy in at reduced prices.Basically, every part of your ideas about investing needs to change, I think. 