Mutual funds. Now, a mutual fund is probably the most popular investment option for retail investors, and it's a professionally managed investment fund where funds are pooled with many other investors. So rather than assemble a portfolio on their own, individual investors and institutions can turn over the selection and the management of their investment portfolio to a third party. Now, most mutual funds can also be referred to as open-ended investment companies and they'll hold stocks, bonds, commodities, and even alternative assets in some cases. Now, in terms of how large the mutual fund industry is, well currently there are about 48,000 mutual funds in over 23 different countries with a total assets of about $20 trillion. So very, very large. So some other key attributes about mutual funds. First, all funds must be registered with the SEC here in the US under the 40 Act. Two, most shares are priced daily to a net asset value. So that means that all shares trade at that NAV and there's no premium or discount to the underlying assets. Next, mostly shares are redeemed by the investment company and not traded. So what does that mean? Well, if investors wanna sell their shares, they need to go to their investment company, or a broker will do it on their behalf, and redeem the shares with that sponsor. You are not trading it in the open market with other investors that may want to buy or sell the same shares. Now, the big exception to all of these points are closed-ended mutual funds. Now, up to this point, we've been discussing what's called an open-ended mutual funds, which is over 95% of the mutual fund industry is structured in that manner. But closed ended funds are different in the sense that they allow no new investments, no new money accepted into the fund. New investors invest by buying existing shares of the fund and investors in the fund that wanna liquidate, they do it by selling their shares to other investors. Therefore, the number of outstanding shares does not change. Hence the name closed ended mutual funds. Now, one of the consequences of this fixed share base is that, unlike open-ended mutual funds, in which new shares are created and sold at that current NAV that we discussed, close-ended mutual funds can sell for a premium or discount to net asset value depending on the supply and demand for the shares in the open market. Now, let's dig deeper into the differences between closed-ended funds and open-ended funds and more specifically the advantages and disadvantages. First of all, open-ended funds. One advantage is that it's easy to grow in size. There's no limit on the amount of shares that can be created. The price always equals the NAV at the end of the day, which is attractive, potentially, to investors. But disadvantages are one of the consequences of the structure is the need to liquidate assets that the portfolio manager might not want to sell at the specific time to meet redemption. So the manager continuously needs to manage cash in and out of the fund. In addition, since there is always a potential for redemption from the fund from investors, there's a certain level of cash that needs to be available to fill those redemptions. Now, close-ended funds, they don't have these problems. There's no cash flow to manage. In trades intra-day with investors trading with each other and prices are dictated by supply and demand. However, because of the structure, they do have a limited ability to grow and since there's a limited amount of shares that could be potentially less liquidity for investors to trade the asset. Now, as a result of these two pretty large disadvantages, of the total net asset value of US mutual funds, only about 2% were in the forum of closed end funds. So a very small percentage.