The Median Is the Truth Serum: How to Read the Market When One Trophy Sale Warps Everything
The latest fortnight (Dec 30, 2025 – Jan 12, 2026) is the perfect example of why collectors should never read a market off totals alone. GPAnalysis tracked $19,205,091 in sales across 18,890 graded books at a $95 median—but the headline sale was Action Comics (1938) #1 CGC 9.0 at $15,000,000 via ComicConnect.
When a single book like that lands, it doesn’t just top the chart… it bends it.
Source: GPAnalysis.com, sales recorded from December 30 to January 12, 2026.
The $15M Fortnight: Top 5 Title Sales by Era — Dec 30, 2025 to Jan 12, 2026. See the full dataset.
What happened this fortnight (in plain terms)
That $15M sale accounted for ~78.1% of the fortnight’s total dollars.
So while the total reads like a rocket launch, most of the market was actually moving in a far more “normal” band underneath.
A simple way to see it:
Average (mean) price including the $15M sale: about $1,017 per book
Average (mean) price excluding that one outlier: about $223 per book
Median price the whole time: $95
That’s the lesson: the mean can be hijacked; the median is harder to bully.
Market Observations
1) Totals tell you what happened at the top. Median tells you what happened everywhere else.
This fortnight’s total sales number is real—but it’s basically a trophy-book headline with a market attached. The $95 median is the clue that everyday collecting activity didn’t vanish when the ceiling exploded.
2) Outliers don’t “invalidate” the fortnight — they just change what the totals mean.
A record sale doesn’t make the market fake. It makes the market lopsided. If you want to understand collector behaviour, you have to read the core, not the headline.
3) Use a “two-lens” approach: Core vs Crown.
Crown (Top-End): the once-in-a-generation book that defines the news cycle.
Core (The Rest): the thousands of transactions that define the hobby’s real heartbeat.
This fortnight’s core still moved 18,889 books after removing the trophy sale.
4) Liquidity doesn’t care about headlines — it just keeps moving.
Even with the whole fortnight dominated by Action #1, the most-traded title was still Amazing Spider-Man (1963), at 1,244 copies and ~$0.5M. That’s your reminder that the market’s “engine room” continues to turn.
5) Era rollups will look “wrong” when one era contains the trophy. That’s normal.
Platinum/Golden looks monstrous in the era bar chart this fortnight because it contains the record. That doesn’t mean the rest of the eras collapsed—it means one transaction overwhelmed the comparison.
A simple framework you can reuse every fortnight
Here’s a handy way to read any dataset: start with the median and volume, check whether one big sale is skewing the totals, compare mean vs median for distortion, then look at the most-traded titles/issues to see what’s really moving.
Step 1: Start with the median
Median wins because it’s hard to distort: a handful of monster sales can hijack totals, but the midpoint stays honest. It’s the cleanest read on how the average collector is behaving, even without a full distribution chart.
How to read it:
Median up + volume up: broad demand is rising (collectors are paying more and buying more).
Median flat + volume up: healthy participation (more activity, pricing stable).
Median down + volume up: bargain-hunting / more lower-end supply entering (could still be healthy, just a different mix).
Median up + volume down: top-heavy demand or tighter supply (fewer sales, but at higher prices).
This fortnight example: median $95 + volume 18,890 = the base market stayed active even with a $15M headline.
Step 2: Check concentration
What it tells you: whether the data’s total sales figure reflects the wider market — or whether it’s really a single-book headline with everything else underneath it.
Key question: ‘How much of total sales came from the top 1 sale?’
Optional (even better): if you have it, check the Top 5 share too — some fortnights are shaped by a handful of big books, not just one.
Rule of thumb buckets:
Under 10%: totals are broadly representative — you can trust the headline.
10–25%: still market-led, but one event is meaningfully tilting the week.
25–50%: top-heavy — totals need context, don’t treat as a ‘normal’ period.
50%+: headline-driven — totals are basically a trophy sale plus everything else.
This fortnight example: top sale was ~78.1% of all dollars → totals are headline-driven, not broad-based.
Step 3: Sanity-check the mean vs median
This is your quick read on skew: whether the fortnight looks like a normal spread of sales or a lopsided shape pulled upward by outliers. It matters because the mean is what most people treat as the “average price paid,” but it’s also the easiest stat for a handful of big sales to hijack.
Quick way to read it:
If the mean ≈ median (or 2–3× median): pretty normal for collectibles.
If the mean is 5×+ median, the data is being pulled upward by major outliers.
If the mean is 10×+ median, the total is heavily distorted; use median + volume for the real story.
This fortnight example:
Mean incl. outlier ≈ $1,017
Median = $95
That’s ~10.7× higher → classic outlier distortion.
Bonus move: compute a “headline-removed mean” (drop the top sale and one unit). It instantly reveals what the rest of the market looked like. Here it was ~$223.
Step 4: Look for liquidity leaders
This shows what collectors are actually buying at scale — the engine room of the market.
What to look for:
Most traded titles: tells you what’s liquid and easy to move (often blue-chips).
Most traded issues: tells you what’s currently “hot” in a very real way — these are the books that are actually changing hands, not just being talked about.
Cross-decade repeats: when the same issues keep appearing, that’s “collector staples” behaviour (a stability signal).
How to interpret it:
Liquidity leaders showing up consistently = the market has a dependable backbone.
If liquidity leaders change suddenly = could be a new media cycle, a new #1 heat, or a seasonal shift in what’s being listed/bought.
This fortnight example: The most-traded title was Amazing Spider-Man (1963), with 1,244 copies and ~$0.5M — proof that the core market kept moving beneath the trophy sale.
Wrap up
This fortnight is a masterclass in market reading: a historic top-end moment paired with a $95 median and nearly 19K books traded underneath it. The trophy sale makes the headline, but the median—and the volume—tell you whether the hobby is still alive at the edges.
If you want a single rule to keep in mind: when the ceiling explodes, trust the median first.
