receiving over $4 trillion worth of funding by rehypothecation, much of it sourced from the UK where there are no statutory limits governing the reuse of a client's collateral. It is estimated that only $1 trillion of original collateral was being used, meaning that collateral was being rehypothecated several times over, with an estimated churn factor of 4. Following the Lehman collapse, large hedge funds in particular became more wary of allowing their collateral to be rehypothecated, and even in the UK they would insist on contracts that limit the amount of their assets that can be reposted, or even prohibit rehypothecation completely. In 2009 the IMF estimated that the funds available to US banks due to rehypothecation had declined by more than half to $2.1 trillion due to both less original collateral being available for rehypothecation in the first place and a lower churn factor. The possible role of rehypothecation in the financial crisis of 2007–2008 and in the shadow banking system was largely overlooked by the mainstream financial press, until Dr. Gillian Tett of the Financial Times drew attention in August 2010 to a paper from Manmohan Singh and James Aitken of the International Monetary Fund which examined the issue. Rehypothecation in repo agreements Rehypothecation can be involved in repurchase agreements, commonly called repos. In a two-party repurchase agreement, one party sells to the other a security at a price with a commitment to buy the security back at a later date for another price. Overnight repurchase agreements, the most commonly used form of this arrangement, comprise a sale which takes place the first day and a repurchase that reverses the transaction the next day. Term repurchase agreements, less commonly used, extend for a fixed period of time that may be as long as three months. Open-ended term repurchase agreements are also possible. A so-called reverse repo is not actually any different from a repo; it merely describes the opposite side of the transaction. The seller of the security who later repurchases it is entering into a repurchase agreement; the purchaser who later re-sells the security enters into a reverse repurchase agreement. Notwithstanding its nominal form as a sale and subsequent repurchase of a security, the economic effect of a repurchase agreement is that of a secured loan. Hypothec by jurisdiction Scotland The law of agricultural hypothec long caused much discontent in Scotland; its operation was restricted by