We're taking a look at the liabilities and shareholders equity section of Goldman Sachs' financial statements here. And we're going to drill down into the line item which is called "Financial instruments sold, but not yet purchased at fair value". It's a big number, $117 billion. And this represents the liability side of the market making business. And we're gonna take a look at a little bit of detail of what's in this item and the mechanics of how it works. So this is the market making liability. There'll also be an asset related to market making as well. If you take a look at the detail, you can see that we've got a breakdown here in the notes. And on one side we've got the assets involved in market making. And you can see that that's a broad spread right across the different financial products. And also there's a fair slug of derivatives down there, 53 billion. But we're actually interested in the financial instrument sold but not yet purchased. And these are effectively short sold securities and you can see that they're focused in specific areas. So we've got a fair slug here of government bonds and government agency bonds. We've also got some corporate loans and debt securities and then a fair slug of equities and convertible to ventures there. There's also a significant amount of derivative short selling as well. And this all reflects the market making activity of Goldman Sachs. If we take a look at the impact on the income statement, you can see that this is a pretty significant business and it's spread into different buckets here. And this is looking at the notes between credit, currencies, equities, and commodities. So in 2016, the market making activities is $9.9 billion. So a significant amount of money. Be careful because a lot of this activity is not necessarily just done on its own in isolation. So often this activity is connected to other transactions or hedging activity as well. So it's quite difficult to look at this in isolation. It's worth actually having a detailed look at the mechanics of selling short. And what we've done here is simplified things significantly just to give you a taste of exactly what's going on here. So let's take a situation where a trader borrows and then immediately sells the security for a $100 and then happily the security is gonna fall to $90 before the settlement. Now we're not going to look at the mechanics and the accounting of borrowing the security, we're going to look at the sale and the effect of the fallen price. So assume that the borrowing has already taken place. And then what happens is we agree a sale of the security and we will record a receivable 'cause we expect to get a $100 from the person we sold it to. And then we create a liability, which is the sold but not yet purchased, because we actually don't have the security to sell 'cause we don't own it. And that would be a liability of 100. Then because the price has dropped of the security, it means that actually we're not going to have to spend a $100 to go out and buy the security. We're only going to have to spend $90. So what we'll do is mark to market that liability of the sold but not yet purchased down from a hundred to 90. And at the same time, we'll book a profit of 10 and that profit will go through the income statement as a market making profit and hit retained earnings which you can see here on the liability and equity side of the balance sheet.