ETF investing is a type of investment fund that is based on the stock exchange similarly to stocks. Here ETF stands for 'exchange-traded product', and an ETF holds assets which may include stocks, bonds and / or trades at roughly similar price to the net value of those invested assets on that trading day. As such then, the owner of the ETF then holds those stocks or bonds, though only authorized personnel can buy or sell the shares of the ETF to or from the fund manager. Normally the stocks or shares beneath the ETF share a common theme tying them together. This might be the region for example, with the multiple shares or stocks being from a certain region allowing you to support an area (such as Southeast Asia for example), or might be in the same industry or trade (for example they might be publishing shares, or might all be in the oil trade).
The majority of ETFs track an index, and are a low cost, tax efficient alternative to stocks. ETF investing is particularly useful for smaller investors as it allows them to have immediate diversifications – owning the multiple stocks, bonds and trades within the ETF with few limitations. This diversification then keeps them safer in an unstable market particularly as they haven put all their eggs in 'one basket' as it were, but at the same time nor have they had to track down multiple shares and have achieved this diversification much more easily. Like stocks they can be traded intra-day and are usually optional.
ETFs are growing in popularity, possibly due to increased interest for the stock market. Many ETF investments now outperform mutual funds and the current total for all ETF assets now exceeds over 1 trillion US dollars. One recently very popular innovation in ETF investing is leveraged ETF. Leveraged ETF is designed in order to make twice or three times the return of the underlying index on a daily basis. This is different from other ETF that only wants to mimic the price of the index and works by including both securities in the underlying index and derivatives of those securities and the index itself. Of course this means higher risk investing, but as a result it also promises higher higher returns (but then this is the nature of all investments where the more you gamble the more you are able to win). Currently 2x and 3x leveraged ETF is the most popular, but this may change (and grow) in future.
Most online brokerages now incorporate ETF scanners to allow them to be looked up by industry sector or region, or alternatively by value or strategy (eg growth, income or speculation). You can also use these to search for leveraged ETF and 2x and 3x leveraged ETF. Cross searches are of course also possible to allow you to find the ETFs for you. For a great way to start investing and to get diversification with low expense ratios and tax efficiency then, look into ETF investing and leveraged ETF.