In times of crisis, okay, when it's not just a matter of trying to influence the economy around the edges, but there's these liquidation events that are happening, and you're worried about a liquidity spiral. And I talked about three stages of crisis. A mild, or I called it normal crisis, okay, that the Fed might be able to handle just by moving around the fed funds rate, okay? By lowering the fed funds rate. And what it is doing when it's lowering the fed funds rate? From the point of view of crisis, it's saying, I know you're having difficulty paying your bills, meeting your settlement. I'm going to make it cheaper for you to roll it over into the future. You don't have to meet your settlement, okay? I'm going to help you here. Pay it later, pay it later. [COUGH] That's the point of this is to relax the survival constraint, in the short run, in order to take off the pressure. And, maybe that works. But, if the imbalance that's leading to people having difficulty paying their bills is big enough, [COUGH] then you have a bigger problem. A medium size crisis, Okay, you may start having to have something influencing the term rate. Okay, and we saw that that's what the Fed did, okay, as the crisis got worse in 2007. Right, it started to lend to dealers, lend to dealer in term, lend to them 30 days, 3 months, something like that. Okay, and not only the term rate in the US, but also $LIBOR. Lend to foreign banks that are borrowing. So, this is intervening directly in the term market here. Instead of relying on, let me mess with the fed funds rate here and let dealers decide what they want to do here. The dealers were having trouble, they were bankrupt. They were not willing to make markets. So the Fed did it. Okay, so the Fed stepped in and became this sort of an entity during the crisis. Normally, it's just setting the target right here, right here. Okay, it stepped in and became this kind of an entity, and that wasn't enough. And so ultimately it dealt with asset prices. Buying mortgage-backed securities itself. Okay, and that is acting like this kind of a dealer here. So, we're going to hear more about that after the midterm, but just for the sake of completeness, I think it's helpful to just have in mind this difference between normal monetary policy. Where you're just messing with the overnight rate here, and letting arbitrage and private profit seeking dealers translate that into asset prices. Which has some sort of indirect effect on credit, okay? That's the normal mechanism. But in a crisis, the dealers stop doing this job. Okay, so you can do anything you want with the Fed funds rate and it never gets into these prices. It never gets in there, okay? Because there's no one who's taking both sides. There's no one translating here and so the Fed itself takes this over in the term market and then in ultimately in the asset price market here. Okay, that's the sort of big picture that I think is helpful to have in your mind as a story of sort of at the highest level of abstraction, what's happening in the money market and why it's important. As you go back and you study and you look at the details of repo and Euro dollar you can get lost in those details, okay. But if you have a big picture, you know where each of those details fits, you know how it connects to this big picture. And remember how we started the course with this big picture? The natural hierarchy of money, and I showed you this. Okay, so now I'm returning to that, and reminding you that we're still talking about the same thing. Okay, we're still talking about the same thing, we just now know a lot more. We have apparatus to talk about settlement risk, to talk about market making, to talk about dealers. We understand about this business about straddling different layers of the hierarchy, and if dealers stop straddling then the markets go away, and prices become uninformative.