Don't try to time the market, it's a fool's game. Do regular purchases of a broad index ETF (exchange traded fund, low fees!), AKA dollar cost averaging as anot

Don't try to time the market, it's a fool's game. Do regular purchases of a broad index ETF (exchange traded fund, low fees!), AKA dollar cost averaging as another child mentions. If you are worried about downswings, keep your portfolio balanced to roughly 50% equities and 50% bonds (there are broad bond index ETFs too).