The Eight FLD Interactions, A Through H

One full 80-day cycle brings price to its 20-day FLD eight separate times — a rise and a fall inside each of the four 20-day cycles stacked within it. We letter those eight meetings A through H, and each has its own character: some carry the cycle's real moves, some exist mostly to set up the one that follows, and every one of them reads differently depending on whether the 80-day cycle is bullish or bearish.

Learn the sequence and you stop seeing random chop. You start seeing a cycle telling you what kind of cycle it is, one interaction at a time. That's the skill this page teaches.

What is an FLD interaction, exactly?

An FLD — future line of demarcation — is past price displaced forward in time by half a cycle. That's the whole construction, and I walk through it properly in What is an FLD?. The 20-day FLD is the version this method leans on hardest, because it divides the 80-day cycle — the workhorse of the nominal cycle ladder — into eight distinct times of interest.

The arithmetic is simple. An 80-day cycle contains four 20-day cycles, back to back, troughing together at the start and the end. Each 20-day cycle spends roughly its first half rising and its second half falling. Four cycles, two halves each: eight windows. In every window, price meets the 20-day FLD in some way — crosses it, rides it, gets rejected by it, or fails to reach it at all. Each of those meetings is an interaction, and the letters A through H are simply the count, in order.

The interactions are observable and repeatable across every 80-day cycle. The trend changes; the sequence doesn't. That's what makes them worth studying every single cycle: the letters are the constant, and how price behaves at each letter is the variable that tells you about the trend.

What are the eight interactions?

Here is the full sequence. Day counts are approximate calendar days into the 80-day cycle, which averages about 68 days trough to trough and ranges roughly 60 to 80.

Two structural notes worth fixing in your head. D lands at the end of the first 40-day cycle — the midpoint turn of the whole span. And the trough that ends H is the trough that ends the 80-day cycle itself, because the fourth 20-day cycle and its parent bottom together — that's synchronicity. H's ending is A's beginning. The sequence is a loop, and it runs about five times a year.

What is each interaction's character?

The definitions above are the skeleton. The character notes are where the reading skill lives — the same letter behaves very differently in bullish and bearish cycles, and that difference is the information.

A — the first rise. The new cycle's opening push off the trough. In bullish 80-day cycles, price crosses the FLD and overshoots its upside projection. In bearish ones, it tends to just meet the projection and fail to go on. A carries the least information of the eight — the cycle is brand new and you know nothing about its character yet — which is exactly why the letters that follow matter.

B — the first pullback. Price falls back toward the line around day 14. In bullish cycles the FLD holds it: price doesn't get far below before buyers show up. In bearish cycles the downside projection gets met, sometimes overshot, before the reversal back up. Either way, B's real job is diagnostic. How far the pullback carries is your first clean read on the cycle's character, and it sets up C.

C — the cleanest rise. After B finds its low, bullish cycles rush upward — often an all-day trending move once price clears the prior day's high. Bearish cycles fail at or before the peak that preceded B, with little new ground gained. C is the interaction with the most information behind it — by the time it arrives you've watched A and B resolve — which is why it's the clearest read in the sequence. It only comes around about once every 68 days.

D — the midpoint turn. The first 40-day cycle ends here, around day 33. In flat and bearish cycles, price falls through the FLD and can overshoot the downside projection — in deeply bearish cycles the move can run toward the 80-day trough itself. In bullish cycles, price barely dips below the line, or holds above it entirely. These moves tend to resolve fast — a day or two — and reverse quickly out of the 40-day trough.

E — the second wind. A new 40-day cycle turns up around day 40, and price firms again — even inside downtrends, which is where E surprises people. It behaves like A but usually carries less far, because the 80-day cycle has passed its midpoint and is starting to lean down. When a major bottom is recent, E can extend well beyond its own projection.

F — the late pullback. From about day 50, price starts down toward the third 20-day trough. In sideways-to-down markets the fall crosses the FLD with ease and stays below — potentially all the way to the cycle trough. In bullish markets F is shallow and shaky: price undershoots the downside projection and turns back up soon after touching the line. F typically lasts about ten calendar days before G develops.

G — the sister of B. A rise around day 60 that fights the current of both the 40- and 80-day cycles, which are now pointed down. In bearish cycles price may reach toward the FLD and never quite touch it, drifting sideways for days. Only in a truly emotional, very bullish market does G amount to much. Its job in the sequence is to set up H.

H — the last fall. Around day 65, the clearest of the four falls. It develops quickly and finishes fast — sometimes in a day or two — as price runs down into the 80-day trough, occasionally extending to meet projections from cycles larger still. The book's examples show H's character holding even inside uptrends, which is unusual among the falls.

Which interactions carry the sequence — and which do we leave alone?

The rises A, C, E and the falls D, F, H are the ones with real character. B and G are the two the method deliberately stands aside on — not because nothing happens there, but because both are counter-current moves whose information value exceeds their move value. B is a fall inside a rising 40-day cycle; G is a rise against a falling 40 and 80. Each exists, in practice, to set up the interaction after it.

The rules of thumb the book distills: in bull trends, usually only H — and sometimes F — has real downside character, while A, C and E carry the advance. In bear trends the falls extend and the rises get muted. And when the phasing is unclear, the 20-day FLD itself is the guide, not the higher-cycle count.

Notice the shape of that: the same eight letters, but the trend decides which half of the alphabet does the work. Which kind of cycle you're in is its own read — it shows up in where the cycle's peak lands inside its span — and I cover that in left vs right translation.

How do projections fit into the interactions?

Every interaction gets measured against a projection. When price crosses the FLD, take the distance from the most recent trough (for a rise) or peak (for a fall) to the crossing point, and project that same distance beyond the cross. That's the expected extent of the move, and reaching about 90% of it counts as met. The full mechanics are in FLD crossings.

What matters here is how each projection resolves. Bullish cycles overshoot upside projections and undershoot downside ones; bearish cycles do the reverse. So every interaction hands you a data point: did the move meet its projection, beat it, or fall short? Eight interactions, eight data points — and by mid-cycle you have a working verdict on the cycle's character, built from evidence instead of opinion.

What does the read look like in real time?

I say these reads on video, with a date on them, and score them afterward — hits and misses both live in the ledger. Here's a miss that teaches the right lesson:

July 9, 2026 — scored a miss. With the S&P weak and a D interaction approaching, I said on the show that our bear scans were "gonna turn completely red" over the next several sessions, and named the window — the next session through the following Wednesday. That window closed green. The roll-over did come, but one to two sessions after the window shut. Right idea, early on timing — and it went in the ledger as a miss, because a call that names a window gets scored against that window.

That's the honest version of how the letters behave. The D interaction arrived; the market just kept its own calendar. The interactions tell you what kind of move is due. Variation decides exactly when it lands.

Where does this read break down?

Four places, and I'd rather you know them up front.

1. Variation. The 80-day cycle averages about 68 days and ranges 60 to 80. Every day count above is approximate, and the letters drift with the cycle. After a large decline that completes a major cycle projection, the following 20-day cycles can run contracted and fast — the book documents this — which compresses the whole alphabet.
2. Bad phasing means wrong letters. The letters are counted from the last 80-day trough. If the trough count is off, you'll read C where D belongs, and the characters stop matching. When the count is uncertain, the FLD itself is the guide.
3. Tendency, not law. Every character note above is a tendency observed across many cycles. Nothing in cycle work is guaranteed — we never guarantee outcomes, and the method's own principle of variation says exactly why.
4. Absence is information. Sometimes an interaction simply doesn't appear — price goes sideways around day 55 instead of making an F, say. That's not a failure of the model; it's one of its loudest signals (more below).

The interactions are one layer of a larger stack — phasing, projections, trend. The whole method, end to end, is laid out in the methodology hub.

Questions traders ask

Do the eight letters apply to cycles other than the 80-day?

The lettering is defined on one specific pair: the 20-day FLD read against the 80-day cycle. The structure that creates it — a cycle containing four of its quarter-length harmonics, each with a rising and a falling half — repeats up and down the cycle ladder, so the logic transfers in principle. But the characters described here were studied on the 80-day/20-day pair, and that's where I trust them. I don't assume a letter's personality survives a change of timeframe untested.

What does it mean when an interaction doesn't show up?

It's information, not a malfunction. The clearest example is a missing F: if price goes sideways around day 55 and bounces instead of breaking down, the cyclic pressures have changed — sellers simply aren't there, and the cycle should stay bullish going forward. A muted or absent interaction is one of the strongest tells the sequence produces.

Why doesn't the method act on B and G?

Both are counter-current. B is a fall inside a rising 40-day cycle; G is a rise against a falling 40- and 80-day cycle. The moves tend to be small, hard to time, and quick to reverse — but what they reveal is valuable. How deep B carries tells you the cycle's character early. G's sideways drift builds the structure whose break defines H. The method treats both as setups to study, not moves to chase.

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