Every mass tort looks inevitable in retrospect. The plaintiff bar talks about it as though the theory was sitting there the whole time waiting to be picked up. In practice, the eighteen months before a JPML petition are noisy, and most categories that look like they are forming never consolidate at all.
The question worth answering is not "is this a real tort." It is "is this category accelerating in a way that survives contact with a transferee court."
Three signals that actually separate
Filing velocity, not filing volume. A category with 400 cases filed steadily over three years is a mature category with a settled bar. A category with 90 cases filed in eleven weeks, concentrated in four districts, is forming. Acceleration is the signal; the absolute count is mostly a description of who got there first.
Court concentration. Early filings scattered across twenty districts usually mean individual firms testing individual theories. Filings clustering into three or four districts means the bar is converging on a venue, which is the practical precursor to a consolidation petition.
Defendant breadth. A theory naming one manufacturer is a product case. The same theory spreading to corporate parents, distributors, and adjacent products in the same class is a category. Watching the named-party list widen is often the earliest reliable tell.
What the signals do not tell you
None of this speaks to causation. A category can accelerate on a theory that will not survive a Daubert challenge, and filing velocity looks identical either way. Several categories we track carry strong procedural momentum and, in our read, weak general causation. Those are worth watching and not worth building a book on.
This is the part that cannot be automated. Velocity scoring narrows the field to the handful of categories worth a serious look; the read on whether the science holds is still a litigator's judgment applied to the underlying literature.
Why this is an intake problem, not a research problem
The firms that do well in an emerging category are not usually the ones with the best analysis. They are the ones whose intake was ready when the category broke: qualification criteria written, SOL exposure mapped by state, record requests templated.
The gap between "we should look at this" and "we can qualify a case in this category today" is typically six to eight weeks of internal work. Compressing that gap is worth more than detecting the category two weeks earlier.