In looking at the chart, the large amount of trustee sales in January 2013 appears to be overflow from repeated sale postponements in 2012. We haven't yet seen the stats on completed trustees' sales for those (first) NOD's filed in 2013.
The lower number of current NOD filings in comparison to past years is NOT indicative of borrowers catching up on all their back principal and interest owed. It is indicative of borrowers cooperating with their lenders in a loan mod, many of which no doubt have "equity-sharing" arrangements built into them with their 1st or 2nd trust deed holder in exchange for being allowed to pay a 2% or 3% fixed rate and have some or all of their deferred interest and/or late charges forgiven. This deferred interest arose from when these borrowers' mortgages exceeded 125% LTV due to them choosing to pay Option 2 (insufficient to fully amortize) and/or Option 3 (I/O) and/or Option 4 (less than I/O - this choice was not avail on all Option ARMS) for a period of months or years. My guess is that these "equity sharing" provisions will be lifted or lessened if borrowers pay their mortgages under the new, modified terms for X amount of years faithfully, in full and on time.
The result is the same. These many thousands of properties are off the market for the foreseeable future unless these borrowers HAVE to sell for reasons of employment, death or divorce.