Rolling returns. Now, when measuring returns, we have many different options, and they generally fall into two categories, a single period measurement and a multiple time period measurement. Now, that multiple period measurement is generally known as a rolling return measurement while single period is just a single period trailing return. Now, they might sound similar, but trailing and rolling returns, they provide a distinct view on an investment's past performance, and even though a single period trailing return is most commonly cited than rolling return numbers, both can be pretty useful as part of an analytical process in measuring performance. Now, a single period return is the most common calculation, as I mentioned, and there's really only one way to do it for a specific time period. The single period trailing return looks backwards from a particular date for a fund or an investment's annualized return over that specific time period. Now, rolling returns display returns in overlapping cycles, and the goal is to show you the frequency and the magnitude of an investment's good and bad performance periods. Now, rolling returns or multi-period returns can be calculated in several ways, and they do not need to be based on calendar years. The period can be tied to the time period for which the security's actually held and is based upon the average annualized returns during that period. Now, before we take a look at a recent example, it's important to remember that rolling returns offer a useful look into an investment or fund's more broad history. It can help investors see through the clouds caused by some more recent data. By looking at rolling returns, we can get a better appreciation for how an investment's returns stacked up at any point in time, not just through the last month or quarter or year. And in this example, we'll first take a look at the MSCI Emerging Market Index, a three-month trailing period return. And this chart spans from June of 2018 through the beginning of September 2018. So just one discrete period that includes some of the worst recent months for emerging market stocks with a negative return for the period of about 10% just in three months. When we look at rolling returns over a three-month period, however, we can look back three years or longer to see how the index or EM stocks stacked up in every three-month period throughout the relevant history, and it gives us a wide range of market types. In this case, rolling returns show strong returns in most three-month periods, resulting in an average annualized return of over 11%. So you can see how the different measures can tell different stories.