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Using 13F Holdings and Form 4 Filings to Study Equity Positioning

Article Machine Learning for Trading

Summary

This reference describes two public SEC filing sources for studying equity positions and insider activity. Quarterly 13F reports provide institutional holdings, either for a curated set of managers or through bulk data covering a full filing window. Form 4 filings record insider transactions for selected tickers. The guide outlines how the data can be downloaded, loaded, and organized for later analysis, including stock-level features and institution-to-stock ownership links.

A key analytical detail is that the holdings data retains both the quarter-end report date and the later public filing date. These dates distinguish when a position was held from when researchers could have observed it, a necessary consideration when building time-aware features or avoiding look-ahead bias. The document identifies downstream uses such as ownership graphs, crowding signals, asset embeddings, and insider transaction analysis, but presents no empirical results or trading strategy. Coverage depends on the chosen managers, tickers, or bulk filing period, and the filing sources describe reported positions and transactions rather than a complete, continuously updated view of current holdings.

Key ideas

  • 13F filings can provide quarterly institutional holdings for selected managers or a broader filing universe.
  • Form 4 filings provide public records of insider transactions for selected equities.
  • Keep report dates separate from filing dates to distinguish position timing from public availability.
  • Ownership links and stock-level features can support crowding and institutional network research.
  • Filing datasets have defined coverage and timing limits, so they are not a real-time view of positions.

Tags

EquitiesUS marketsPortfolio constructionEvent-driven
Full text
# Equity Positioning: 13F + Form 4


# Equity Positioning: 13F + Form 4

SEC regulatory filings that capture **positions** and **insider activity**
at the equity level. All data is public domain (SEC EDGAR). Respect the
10 req/sec rate limit via a descriptive `User-Agent` — downloaders here
handle this automatically.

## Datasets

| Dataset | Filing | Universe | Script | Loader(s) |
| --- | --- | --- | --- | --- |
| Institutional holdings | 13F | Curated 10 managers (per-cik) or full universe (bulk) | `13f_download.py` | `load_institutional_holdings_13f`, `load_13f_stock_features`, `load_13f_edges`, `load_13f_bulk_holdings` |
| Insider transactions | Form 4 | User-chosen tickers | `form4_download.py` | Raw XML — read directly via `pathlib` (see Ch4 NB 03) |

## Download Commands

```bash
# === 13F (institutional holdings) ===

# per-cik (default): 10 curated managers, 4 most recent 13F-HR filings each
uv run python data/equities/positioning/13f_download.py
uv run python data/equities/positioning/13f_download.py --num-filings 8
uv run python data/equities/positioning/13f_download.py --max-institutions 3

# bulk: one or more quarterly filing windows (SEC's own labels)
uv run python data/equities/positioning/13f_download.py --mode bulk --quarters 2024Q3
uv run python data/equities/positioning/13f_download.py --mode bulk --quarters 2024Q2,2024Q3

# === Form 4 (insider transactions) ===

uv run python data/equities/positioning/form4_download.py --ticker TSLA --count 20
uv run python data/equities/positioning/form4_download.py --ticker TSLA,AAPL,MSFT --count 10
```

## Directory Layout

```
$ML4T_DATA_PATH/equities/positioning/
├── 13f/
│   ├── institutional_holdings.parquet       # per-cik: raw holdings (10 curated managers)
│   ├── institution_stock_edges.parquet      # per-cik: institution → stock edges
│   ├── stock_features.parquet               # per-cik: stock-level features
│   ├── coownership_matrix.npy               # per-cik: stock × stock similarity
│   ├── coownership_stocks.txt               # per-cik: row/col CUSIPs
│   └── bulk/
│       └── {YYYYQN}/
│           ├── institutional_holdings.parquet   # bulk: full-window universe (~3M rows)
│           └── bulk_13f.zip                     # cached raw SEC zip
└── form4/
    └── {TICKER}/{accession}.xml             # Raw Form 4 insider filings
```

## Loading

```python
from data import (
    load_institutional_holdings_13f,
    load_13f_stock_features,
    load_13f_edges,
    load_13f_bulk_holdings,
)

# 13F per-cik (curated managers)
holdings = load_institutional_holdings_13f(start_date="2024-01-01")
features = load_13f_stock_features()
edges = load_13f_edges()

# 13F bulk (full universe, one quarter)
q3_2024 = load_13f_bulk_holdings("2024Q3")
```

The holdings schema preserves both SEC dates: `report_date` is the quarter-end
position date and `filing_date` is when the filing became public.

## Consumers

- **Ch4 NB 03** — Form 4 insider-transaction parsing
- **Ch4 NB 05** — Full-universe 13F analysis via `--mode bulk`
- **Ch10 NB 02** — Asset embeddings from 13F holdings
- **Ch22 NB 07** — Institutional ownership graph + crowding signals
- **Ch23** — `09_knowledge_graph_features`, `05_institutional_holdings_kg`, `04_rag_comparison_benchmark`

Shown in full with attribution under the source's licence. Licence: MIT

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.