I prefer ETF's over mutual funds as you have more control over taking profits. I am getting killed on taxes on Capital Gains distributions on positions held for many years by mutual funds. Check Forbes annual issue on funds to get the best information. Can't remember what month that was. Money Magazine also has good information. Vanguard has some great ETFs if memory serves me right. Annual costs are generally lower in ETFs vs mutual funds.
I prefer ETFs as well but USAA refuses to offer any. I assume it's because expense fees are lower and they can get away with charging more expenses for their mutual funds! Looking into taking my high six figures to Vanguard or Fidelity after 37 years of membership with USAA!
ETFs are traded as ordinary stocks. I have had several in my brokerage account with USAA. You can purchase ETFs which mirror the market or some particular segement of the market. ETF is short for EXCHANGE TRADED FUND. The more specialized the segment, the greater the risk. You could purchase an ETF which mirrored the S&P 500, the Dow, or the price of Gold (GLD) or Silver (SLV). Clearly the latter two present the greater risk. If you Google ETFs or SPDRs it will tell you what you need to know. Believing that the price of oil will eventually come back, I recently purchased XLE which has a portfolio of several different companies involved in various aspects of the oil industry, such as refinning, pipelines, distribution, etc. That represents a greater risk than a fund which mirrors the S&P500 or the Forbes 50 or some other index. Index funds tend to have much lower administrative costs than mutual funds and you can decide when to take your profits (or losses) without getting an ugly surprise from the TAX Man.