The Treasury, apparently dissatisfied with the speed of indirect bank and/or Fed-inspired monetization of its exponentially rising debt-load at ever-cheaper costs of funds, decided in June 2011 to allow the Chinese, with their equally large bucket of USDs to bid directly for US Treasuries. As Reuters reports [6], China can now bypass Wall Street when buying U.S. government debt and go straight to the U.S. Treasury, in what is the Treasury's first-ever direct relationship with a foreign government. The documents, viewed by Reuters, indicate that the US Treasury has given the PBOC a direct computer link to its auction system - which was first used in the 2Y auction of June 2011. Perhaps this helps explain the massive spikes in direct bidders July and August 10Y auctions (around the US downgrade). Interestingly, Primary dealers are not allowed to charge customers money to bid on their behalf at Treasury auctions, so China isn't saving money by cutting out commission fees; instead, China is preserving the value of specific information about its bidding habits. By bidding directly, China prevents Wall Street banks from trying to exploit its huge presence in a given auction by driving up the price. This, after the 2009 discovery (and relaxing of other reporting requirements to cover this) that China was using special deals to hide its bond purchases, seems like more pandering to the large-holder-of-Treasuries as "direct bidder status may be controversial because some government officials are concerned that China has gained too much leverage".
If nothing else, it changes dramatically any empirical interpretation of direct vs indirect bidders once and for all...
[7]
Chart: Bloomberg