beginning of the current purchase program in 2012, we have purchased nearly $ 75 billion in mbs on average per month, including reinvestments. this translates into about 50 percent of monthly gross issuance, below the monthly purchase rate of roughly two - thirds during the first round of large - scale mbs purchases in 2009. if refinancing activity declines, leading to a decrease in gross issuance, our purchases could exceed these levels. of course, the pace of asset purchases is not strictly limited by the amount of new mortgage origination, as market participants can also deliver older securities into tba contracts. as the pace of mbs issuance evolves, the desk will continue to watch the market functioning indicators discussed above, with a particular emphasis on the market ’ s ability to settle further purchases. conclusion overall, i believe the desk has effectively and efficiently carried out the fomc ’ s directive to purchase additional treasury securities and agency mbs in a transparent fashion that achieves the fomc ’ s policy objectives, supports orderly market functioning, and obtains competitive market prices. i also believe that the federal reserve ’ s balance sheet policies have been effective in easing financial conditions, particularly with respect to making historically low borrowing costs available to existing and prospective american homeowners, as well as lowering interest rates to spur business investment and household spending. to achieve our policy mandate, we rely on your continued ongoing and active participation in our operations both for your own accounts and for the accounts of your customers, consistent with your role as primary dealers. we will continue to implement the fomc ’ s the desk also purchases dollar roll contracts when implied financing rates are sufficiently positive. such operations occurred in december 2011. see tmpg best practices. selling dollar rolls when concerns arise about the availability of certain tba contracts is conceptually similar to making soma treasury holdings available to the market through our securities lending program. one key difference is that the desk offers settled treasury holdings to the market through its securities lending program, whereas the desk only rolls unsettled mbs holdings. bis central bankers ’ speeches directive, with the goal of supporting a stronger economic recovery in the context of price stability. references fleming, michael ( 2000 ). “ the benchmark u. s. treasury market : recent performance and possible alternatives. ” federal reserve bank of new york economic policy review, vol. 6, no. 1 ( april ) : 129 – 45. fleming, michael ( 2002 ). “

more similar. we examined a range of balance sheet and income statement items, market indicators, and organizational structure data to draw some preliminary conclusions. the results, reported in the appendix, are generally supportive of the notion of greater homogeneity among the largest banks, but a more rigorous assessment of these preliminary conclusions would be a fruitful area of investigation. why do we care? i now turn to a final question – does this matter for supervisors and regulators? i think it does. i will consider four potential reasons why this shift is relevant for the official sector ’ s concern for 3 / 5 bis central bankers'speeches safety and soundness and efficient financial intermediation : a firm ’ s risk management approach, the evolution of supervisory focus, the development of macroprudential risks, and allocative efficiency of financial services. i ’ ll begin with our core microprudential focus on ensuring that banks develop and implement the appropriate risk management infrastructure for their evolving risks. while this is more linked to the changes in business models than greater similarity, the underlying drivers are the same. as banks respond to environmental factors by expanding into new activities or shifting their strategic focus, they naturally face new risks and must adapt their risk management infrastructures along with their evolving business models. this entails ensuring the appropriate level of expertise about the new businesses ; assessing that all relevant risks are identified, monitored, measured, and managed for each business line and the firm as a whole ; and establishing the appropriate interaction with the enterprise risk management functions and boards of directors. these are core parts of supervisory expectations for traditional risk management and banks need to ensure that they are applied appropriately as they evolve. moreover, expansion into new activities can bring entirely new risks beyond the direct risks of each specific business. for example, a firm that expands by offering a broader set of products to its existing base of customers. this has the potential to introduce greater correlation of business line results and a different type of shock if a financial firm potentially loses multiple revenue streams should a single customer face distress. alternatively, a firm might be inclined to use one business line to cross - subsidize another, which makes measuring and managing risks and allocating capital more difficult from a business line perspective. in both cases, the potential risks would need to be managed at the enterprise level to reflect these cross - business linkages. a second implication is the need for the supervisory community to be responsive to the evolution of firms ’ strategies and business models. as firms