I'm working through the HHI calculation for an industrial yarn merger. The combined entity would have a 20% market share, which falls short of the 25% threshold for trigger (a). The premerger HHI sits at 1658, and after the merger the combined shares would push it to 1850 with a delta of 192 points—exceeding the 1800 threshold but I need to evaluate whether the increase itself meets the enforcement criteria.

For trigger (b) to apply, I need both HHI above 1800 AND an increase exceeding 200 points. Since the increase is only 192, that second condition fails, so there's no structural presumption here. The numbers are close enough that small variations in market shares could flip the outcome—if the firms' shares were just slightly larger, say 13% and 8% instead of 12% and 8%, the delta would hit 208 and cross the threshold.

Turning to the medical mesh market, I'm determining whether the combined entity triggers the 25% share test. The calculation hinges on import volume, which is unverified. At zero imports the combined share reaches 30%, but at $16 million in imports it's exactly 25%, and beyond that it drops below. Since I can't confirm the import figure, I need to treat this conservatively and assume the filing obligation applies unless the data clearly shows otherwise.

The real problem is that I can't compute the postmerger HHI level at all. The verified sellers' shares can be calculated as fractions of the total market including unknown imports, but the $56 million in "other verified sellers" isn't broken down by individual firm, and the import volume remains unallocated. Without knowing how imports are distributed—whether they're concentrated in one large importer or spread across many small ones—I can't determine whether the merger increases concentration or how much. The delta between the two merging firms can be estimated across different import scenarios, but the absolute HHI level is unknowable.

To actually verify the import volume, I'd need to trace customer purchase records, importer documentation, and customs entry data with product-level detail—including bills of lading, commercial invoices, and HS codes—to confirm what was actually delivered into the market during the measurement year, excluding transshipment, re-export, and non-medical products.

The revenue basis matters too: I need to nail down whether we're measuring landed value or resale price to Corda customers, then attribute imports seller-by-seller for HHI purposes while avoiding double-counting anything already in the verified $80M figure. Timeline-wise, we're signing next week with a 35-day close and 10 days for verification, so there's room, but gun-jumping violations run $80,000 per day combined if we close without filing. The yarn market likely doesn't trigger a filing requirement, but I should document the analysis and double-check before finalizing the recommendation.

For the filing trigger itself, the post-HHI sits at 1850, already above the 1800 threshold, so even an 8-point increase would breach the 200-point presumption—any upward revision of either party's share would likely require filing. The combined share test needs just 5 more points to hit 25%, which is less probable. I should order the 10-day verification immediately and condition the close on the results: if verified qualifying imports come in at $16M or below, the combined share hits 25% and we file before closing; if imports exceed $16M, the share test fails and I need to pull the seller-level breakdown of the $56M and imports to compute the HHI properly.

The filing decision hinges on whether post-merger HHI exceeds 1800 with a delta above 200—which triggers whenever imports fall below $23.9M. If verification can't be completed in time or the data's ambiguous, the conservative move is to file anyway. I should structure the deal with a closing condition tied to filing clearance and avoid any pre-closing integration or coordination. Filing now is relatively cheap compared to the $80k daily penalty risk, and given the uncertainty across the range, filing while continuing verification is the safer path.

Since there's still time before the 35-day window closes, I can pursue the data, but I should prepare filing materials in parallel as a backup. If imports land between $16M and $23.9M with delta exceeding 200, I'll need the HHI level to determine filing necessity—and if that's indeterminate, file conservatively. I'm also noting that combining yarn and mesh products to artificially dilute market share isn't permitted under the rules, and I should verify whether Alder and Prism's own product sales are included in the import figures.