Who this entry is for — Anyone looking for the «first signal» that a downtrend is losing momentum. Preliminary Support is not the bottom: it is the first footprint of institutional demand before the climax and the trading range.
Source: Wyckoff Schematics (Pruden, MTA 2006); Wyckoff Analytics teaching. Phase A accumulation event, often subtle compared to the SC.
Prerequisites
Accumulation phases A–E (phase A) and Four-phase cycle — the PS appears as markdown is giving way.
Definition
In plain terms — After a long decline, the stock stops collapsing: bars show rising volume and firmer closes near the lows. Large operators are starting to absorb — but fear is not exhausted yet.
Preliminary Support (PS) is the first phase A event where institutional demand becomes visible on the tape: price slows its fall, lows turn less aggressive, and volume signals that operators with capital are buying without yet pushing the stock into markup. It does not stop the downtrend on its own — the SC often follows, with final panic washing out the last weak holders and concentrating shares in the hands of the Composite Man. The PS has diagnostic value because it anticipates the sequence PS → SC → AR → ST that defines the trading range.
| Feature | Typical PS | Not PS if… |
|---|---|---|
| Context | Mature downtrend | Range already defined |
| Volume | Rising vs prior bars | Record climax (that is SC) |
| Price | Slower decline, first local higher lows | Bounce that breaks trend up |
| Expected follow-up | SC, then AR | Immediate markdown |
Example — Stock from €52 to €40 over ten weeks. At €41, three sessions show volume +35% vs average and closes in the upper half of the bar while still below €42: PS. Two weeks later the SC at €38.50 on 4× average volume; AR to €43 defines the range. The PS was not the entry — it signalled that the accumulation campaign was starting.
Missing PS: reaccumulation and schematic #2
In reaccumulation, phase A is often muted or absent: there is no dramatic downtrend to halt, so PS and SC may be missing (reaccumulation). Pruden schematic #2 shows accumulation without spring — the PS can be equally discreet. Forcing a PS label on every slowdown is a checklist error.
Common mistake — Buying on the PS as if it were the bottom. The PS has not passed the nine buying tests (test 2 requires PS + SC + ST): entering here means anticipating phase A and often suffering the shakeout of the SC or the spring.
Symmetric
The distribution counterpart is Preliminary Supply (PSY) — first institutional selling at the top of the uptrend (PSY).
Summary card
| Abbr. | PS |
| Phase | A (accumulation) |
| Sequence | PS → SC → AR → ST |
| Nine tests | Test #2 (with SC and ST) |
| Symmetric | PSY |