A/HRC/12/31* page 21 late 2005,30 leading to the formation of a speculative bubble on markets for maize, wheat, soybeans and rice.31 While speculation thus understood is not the immediate cause of price increases on the spot market (where commodities are effectively traded), it may nevertheless exacerbate volatility by encouraging hoarding by both private traders and Governments, and because of the relative slowness of supply and demand to react to price changes.32 According to the World Bank, this had a significant impact on prices: “real-side speculation (the decision to hold stocks in anticipation of further price increases or to order more than needed now for the same reasons) likely contributed to the rapid increase in prices during 2007 and 2008”.33 This is also the conclusion reached by UNCTAD in its report on the global economic crisis.34 38. A number of measures could be taken to limit the risks engendered by financial speculation. Certain measures would be of a purely regulatory or institutional nature; for instance, to dampen pure financial speculation, regulators could increase the margin (for example, from 10 per cent to 30 per cent as down payment), as this would force speculators to make a larger down payment for their speculation. The registration of funds trading on agricultural commodities on spot or derivative markets has also been proposed, in order either to exclude hedge funds from those markets or to allow for their activities to be better monitored, for instance by prohibiting certain highly speculative activities, such as short selling or dealing in over-the-counter derivatives.35 The International Food Policy Research Institute has proposed the establishment of a fund managed independently by a high-level group of experts allowed to intervene on the futures markets when prices appear significantly higher than what would correspond to a reasonable margin within a dynamic price band. The group would execute a 30 The International Food Policy Research Institute forum, “Speculation and World Food Markets”, July 2008, p. 9. 31 J. van Braun and M. Torero, “Physical and virtual global food reserves to protect the poor and prevent market failure”, the International Food Policy Research Institute policy brief, 4 June 2008. 32 In addition, higher prices on the futures markets may be misinterpreted by traders as incorporating new market information, thus leading to the formation of a bubble, because all traders will react in a similar way. 33 The World Bank, Global Economic Prospects, op. cit., p. 64. 34 UNCTAD/GDS/2009/1. 35 P. Wahl, “Food speculation: the main factor of the price bubble in 2008”, World Economy, Ecology & Development, 2009.