Industrials ยท Farm & Heavy Construction Machinery ยท Completed evidence
BLBD relative to FSS
Blue Bird Corp is the relatively depressed leg. Federal Signal Corporation is the relatively extended leg.
Specific pair strategy
What is the play in BLBD / FSS?
This is a relative trade. The result depends on which security performs better, not on whether the whole market rises or falls.
Convergence condition active
Long BLBD / short FSS
Treat the two legs as one relative trade. The idea works when BLBD outperforms FSS, not simply when BLBD rises or FSS falls.
This is the relatively depressed leg. The case needs it to recover or at least hold up better than the other leg.
This is the relatively extended leg. The case needs it to lag or weaken relative to the long leg.
A favourable relative move means BLBD rises more than FSS, falls less than FSS, or rises while FSS falls. If FSS outperforms BLBD, the pair moves against the case.
The research trigger is active because the completed daily gap is narrowing while BLBD improves relative to FSS. For a fresh position, require the next completed daily update to continue that move toward normal.
Maintain the case only while BLBD continues to gain on FSS, relationship quality remains usable and the wider evidence does not reverse.
The case fails if the completed gap widens again while BLBD weakens relative to FSS, or if the publication moves into a relationship-break state.
The cleaner confirmation is a narrowing spread led by weakness in the extended leg rather than strength in both securities.
Evidence now
- FSS Market Dynamics is weakening.
What would invalidate it?
A fresh strengthening in the extended leg can prolong the separation and increase short-side risk.
Possible setup paths
How the relative-value idea could be expressed
These are research structures, not recommendations or position-size instructions. The current course above determines whether any structure is ready to study now.
Long BLBD / short FSS
Treat both legs as one relative position. The setup looks for BLBD to outperform FSS; BLBD can rise faster, fall less, or rise while FSS falls. The pair loses ground when FSS outperforms BLBD.
When it becomes relevantThis is the clearest expression to study now because both the weekly evidence and completed daily timing agree. Look for BLBD to keep gaining relative to FSS while relationship quality and evidence alignment hold.Principal riskRequires a live review of both legs, borrow availability and cost, event dates, liquidity and the research normalisation.Study BLBD alone if its own evidence confirms
This simpler expression focuses on recovery in BLBD. It avoids short-borrow mechanics, but it no longer isolates relative value: the result is exposed to the broad market, the sector and BLBD-specific news.
When it becomes relevantA stronger case needs improving BLBD price structure and supporting evidence, not just a wide relationship gap.Principal riskCarries full single-security and broad-market direction risk.Study FSS alone if its support continues to weaken
This expression focuses on weakness in FSS. It may fit a leader-rollover case, but it also abandons the relative hedge and adds direct market direction, squeeze and company-event risk.
When it becomes relevantWeakening in FSS must be visible in its own completed evidence; relative extension alone is not enough.Principal riskShort selling can involve unlimited loss, borrow fees, recalls and forced close-outs.Any practical expression needs an independent review of suitability, portfolio risk, liquidity, current news and earnings, borrow availability and cost, transaction costs and tax.
Relationship gap ยท technical name: standardised residual
How far apart are they compared with normal?
Zero is the pair's historical centre. The outer guides show increasingly unusual departures from it.
This is the relationship gap after allowing for the pair's usual co-movement. Zero is its historical centre; the distance is measured in standard deviations, so different pairs can be compared on the same scale.
The latest gap is 0.83 standard deviations from normal. BLBD is the relatively depressed leg and FSS is the relatively extended leg. That is unusual separation, not proof that either security is cheap or expensive.
A move toward zero means convergence. A move farther from zero means the separation is extending and raises the risk that the old relationship is changing.
Common-base price paths
Which security created the gap?
Both paths begin at 100 so their relative movement is visible without mixing different share prices.
Both securities are reset to 100 at the first date. This removes the distraction of different share prices and shows how their completed weekly price paths diverged. It is not a valuation chart.
Since the common starting point, FSS is +118.6% and BLBD is +206.3%. The chart shows which price path contributed to the separation; the fitted relationship measure is more precise than the raw visual distance.
For convergence, watch for BLBD to catch up, FSS to lose ground, or both. The relationship can close even if both securities rise or both fall.
FSSBLBD
Completed daily timing
Is the gap closing yet?
The daily relationship adds timing context inside the slower weekly case. It does not replace the weekly validity checks.
This applies the same relationship to completed daily bars. It is the timing layer inside the weekly case, not a separate trading signal.
Gap narrowing: The completed daily gap is narrowing. That supports the weekly convergence case, although it still needs to persist.
Further movement toward zero would strengthen confirmation; a turn away from zero would weaken it.
BLBD ยท Blue Bird Corp
64/100 evidence score- Market Dynamics
- 0.166 ยท change -1.543
- Trend
- Positive
- Stage
- Stage 2 ยท Advancing
- Smart Money
- Neutral
- News sentiment
- Positive
- Options
- Bearish
FSS ยท Federal Signal Corporation
67/100 evidence score- Market Dynamics
- 0.675 ยท change -0.415
- Trend
- Positive
- Stage
- Stage 2 ยท Advancing
- Smart Money
- Neutral
- Short interest
- Crowded
- Options
- Bearish
Relationship diagnostics
Why this pair is on the map
How closely completed weekly returns moved together across the measurement window.
How consistent the fitted relationship remained across earlier and later parts of the sample.
An observed mean-reversion clock, not a deadline or a forecast.
How often the residual crossed its historical centre; repeated crossings matter more than a single fit.
The latest residual's location inside its own completed history.
Stored price, volume and size context only. It does not include a live short locate or cost.
1 of 2 non-overlapping historical separations resolved after the relationship was fitted on earlier data.
Median time to return near the earlier fitted centre among the held-out cases that resolved.
The largest further move recorded after a measured held-out separation, before resolution or the observation window ended.
State history
What changed and when
Relationship retired
Removed from the current map because the relationship no longer passed the publication checks.
Daily timing changed
Completed daily timing changed to gap narrowing through 2026-08-21.
Daily timing changed
Completed daily timing changed to gap stable through 2026-08-20.
Daily timing changed
Completed daily timing changed to gap narrowing through 2026-08-18.
Daily timing changed
Completed daily timing changed to gap stable through 2026-08-17.
Relationship discovered
Published as Leader rollover after the completed 2026-08-14 observation.
Same-industry map