Hello, I'm getting into ETFs. I keep buying the S&P 500 ETF while I figure out the other ones. So now I have about 10% of my total portfolio in the S&P 500. I know standard asset allocation often says 60% stocks, 40% bonds until you get closer to retirement. Is it OK to have 15% or even 20% in the S&P 500 ETFs? If it takes me a month or two to research and buy the other ETFs, I can miss out on a lot of the S&P 500 gains (it's moving up a lot this month). I'm not sure what a "no brainer" percentage would be. Kind of like "if you have no better ideas at the moment... it is ok to go up to this percentage without worrying about having too much of the S&P 500." Rather than having the money parked, I've been adding to my S&P 500 ETF position while I learn sensible things to buy in other ETFs (like a "world" etf, or a "bond" etf, etc.). But I don't want to go higher than a sensible percentage. Thank you.