> For the complete documentation index, see [llms.txt](https://statalpha.gitbook.io/statalpha-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://statalpha.gitbook.io/statalpha-docs/stats/pdhlb.md).

# PDHLB

The **Previous Day High/Low Break (PDHLB)** module tracks how often price breaks the previous day’s high or low, measures follow-through, and analyzes retests and breakout strength.\
It provides valuable insights for **opening range setups**, **trend continuation**, and **false-break detection**.

***

## Concept

* Detects when price **exceeds the previous day’s high or low**.
* Measures **follow-through strength**, **retest probability**, and **duration** above/below those levels.
* Calculates **volume ratios**, **relative volatility**, and a **breakout strength score** for both directions.
* Summarizes how consistent such breakouts are over time, including streaks and false-break frequency.

***

## Parameters

| Parameter                 | Type   | Description                                                       |
| ------------------------- | ------ | ----------------------------------------------------------------- |
| `symbol`                  | string | Asset symbol (e.g. `AAPL`, `BTCUSD`)                              |
| `start_date` / `end_date` | string | Date range (`YYYY-MM-DD`)                                         |
| `time_window`             | string | Predefined time range (e.g. `1M`, `3M`, `6M`, `12M`, `24M`, `5Y`) |
| `start_time` / `end_time` | string | UTC intraday range (default `13:30`–`20:00`)                      |
| `include_extended_hours`  | bool   | Include pre-/post-market data                                     |
| `direction`               | string | For `/top` and `/retest`, choose `high`, `low`, or `both`         |
| `limit`                   | int    | Max number of records to return (default `10`)                    |

***

## Endpoints

| Endpoint                   | Description                                                                     |
| -------------------------- | ------------------------------------------------------------------------------- |
| `GET /stats/pdhlb`         | Returns raw day-by-day breakout data with all metrics                           |
| `GET /stats/pdhlb/summary` | Aggregated metrics (follow-through averages, retest rates, volume ratios, etc.) |
| `GET /stats/pdhlb/top`     | Top breakout days by move size (`high` or `low`)                                |
| `GET /stats/pdhlb/retest`  | Days where price retested previous day’s level after breakout                   |
| `GET /stats/pdhlb/doc`     | Returns field documentation for all PDHLB endpoints                             |

***

## Example Requests

### 1. Retrieve raw breakout data

```bash
curl -s -H "Authorization: Bearer $ACCESS_TOKEN" \
  "https://api.statalpha.market/stats/pdhlb?symbol=AAPL&time_window=12M"
```

### 2. Get summary statistics

```bash
curl -s -H "Authorization: Bearer $ACCESS_TOKEN" \
  "https://api.statalpha.market/stats/pdhlb/summary?symbol=AAPL&time_window=12M"
```

### 3. Find top breakout days (highs)

```bash
curl -s -H "Authorization: Bearer $ACCESS_TOKEN" \
  "https://api.statalpha.market/stats/pdhlb/top?symbol=TSLA&direction=high&limit=5"
```

### 4. Find all days with retests

```bash
curl -s -H "Authorization: Bearer $ACCESS_TOKEN" \
  "https://api.statalpha.market/stats/pdhlb/retest?symbol=MSFT&time_window=12M"
```

***

## Example Response (summary excerpt)

```json
{
  "symbol": "AAPL",
  "total_days": 252,
  "high_breaks": 138,
  "low_breaks": 121,
  "both_broken_same_day": 36,
  "avg_follow_through_high_pct": 0.84,
  "avg_follow_through_low_pct": 0.73,
  "retest_rate_high_pct": 57.3,
  "retest_rate_low_pct": 51.8,
  "avg_time_to_max_follow_through_high_min": 38.2,
  "avg_time_to_max_follow_through_low_min": 42.7,
  "avg_duration_above_prev_high_min": 112.5,
  "avg_duration_below_prev_low_min": 94.3,
  "high_break_success_rate_pct": 74.6,
  "false_breakout_rate_high_pct": 13.8,
  "avg_volume_ratio_high_break": 1.42,
  "avg_breakout_strength_score_high": 78.6,
  "avg_relative_close_vs_prev_close": 0.0042,
  "avg_relative_range_vs_prev_range": 1.18,
  "time_window": "12M"
}
```

***

## Interpretation

| Metric                                                            | Meaning                                                        |
| ----------------------------------------------------------------- | -------------------------------------------------------------- |
| **high\_breaks / low\_breaks**                                    | Number of sessions breaking previous high or low               |
| **avg\_follow\_through\_high\_pct / low\_pct**                    | Average % move after breakout                                  |
| **retest\_rate\_high\_pct / low\_pct**                            | Share of days that retested broken level                       |
| **avg\_duration\_above\_prev\_high\_min / below\_prev\_low\_min** | Duration in minutes spent beyond previous levels               |
| **avg\_time\_to\_max\_follow\_through\_high\_min / low\_min**     | Time (minutes) until max follow-through was reached            |
| **avg\_volume\_ratio\_high\_break / low\_break**                  | Relative volume intensity at breakout vs. average              |
| **avg\_breakout\_strength\_score\_high / low**                    | Composite score combining follow-through, duration, and volume |
| **false\_breakout\_rate\_high\_pct**                              | % of failed high breakouts without retest or continuation      |
| **avg\_relative\_close\_vs\_prev\_close**                         | Average daily close relative to previous day’s close           |
| **avg\_relative\_range\_vs\_prev\_range**                         | How the day’s volatility compares to the previous day’s range  |

***

## Notes

* PDHLB is one of the most used indicators for **continuation and reversal probability** analysis.
* Strong breakouts with retests and sustained volume often precede short-term trends.
* False breakouts tend to signal **range compression** or **trend exhaustion**.
* All users can access the same PDHLB endpoints; plan differences affect only query flexibility.


---

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