Waterfall Forensics.

Prime hybrid ARM RMBS

Wells Fargo Mortgage Backed Securities 2006-AR12 Trust.

424B5 filed 2006-08-25, acc 0001193125-06-179659

machine-encoded from the prospectus by the extraction pipeline and tied out over 4 periods (2006-09-25 to 2006-12-26); not yet expert-verified

Backtested periods

4

2006-09-25 to 2006-12-26

Comparison points within $1

100.0%

204 points

Max principal delta

$0.37

interest $0.03 · balance $0.37

What the encoder found in the filings

  • I-B-6: draft face 1,875,749.00 -> reported 1,875,749.85 (pinned from the remittance Original Balance)
  • II-B-6: draft face 1,399,163.00 -> reported 1,399,163.61 (pinned from the remittance Original Balance)
  • group 1 has 3 senior classes (I-A-1, I-A-2, I-A-R); assumed pro rata, but the contract may pay them as components — check the tie-out
  • group 2 has 2 senior classes (II-A-1, II-A-2); assumed pro rata, but the contract may pay them as components — check the tie-out
  • subordinate stack per loan group: encoded as group 1 (3 senior + 6 subordinate), group 2 (2 senior + 6 subordinate) and tied out separately; cross-collateralization after a group's seniors retire is not modelled
  • group 1: window starts at deal month 1 (2006-09-25); earlier reports are not in the machine-readable run
  • group 2: window starts at deal month 1 (2006-09-25); earlier reports are not in the machine-readable run

Capital structure · original faces

I-A-1
$687,585,000.00
I-A-2
$30,519,000.00
I-A-R
$100.00
II-A-1
$647,133,000.00
II-A-2
$25,562,000.00
I-B-1
$17,250,000.00
I-B-2
$5,625,000.00
I-B-3
$2,999,000.00
I-B-4
$2,250,000.00
I-B-5
$1,875,000.00
I-B-6
$1,875,749.85
II-B-1
$15,384,000.00
II-B-2
$4,895,000.00
II-B-3
$2,098,000.00
II-B-4
$1,748,000.00
II-B-5
$1,049,000.00
II-B-6
$1,399,163.61

viridian = senior (per-pool) · burgundy = cross-collateralized subordinates

Worst remaining deltas · computed vs reported

interest

2006-09-25I-A-1-0.03
2006-11-27II-A-1+0.02
2006-09-25II-A-1-0.02
2006-12-26I-A-1+0.01
2006-10-25II-A-1+0.01

principal

2006-09-25II-A-1+0.37
2006-09-25I-A-1+0.14
2006-09-25II-A-2+0.01
2006-09-25I-B-6+0.01
2006-11-27I-B-6-0.01

ending balance

2006-10-25II-A-1-0.37
2006-11-27II-A-1-0.37
2006-12-26II-A-1-0.37
2006-09-25II-A-1-0.37
2006-09-25I-A-1-0.14