De-SPAC Completion-Date Database for Event Studies

A de-SPAC completion-date database should anchor the cohort on consummated business combinations and keep the closing date, disclosure filing date, and first trading date under the new ticker as separate clocks.

Alphanume De-SPAC Events contains completed SPAC business combinations identified from SEC filings, typically the expanded closing disclosure known as a Super 8-K. Proposed, pending, and terminated deals are outside the dataset. One row represents a confirmed transition from a blank-check company into an operating company.

The endpoint is GET /v1/de-spac-events. It returns the post-combination ticker, source filing, evidence, company identity, listing dates, redemption and financing fields, and transaction values when supporting filings state them. This is an event source, not a claim that every completed SPAC will underperform or that completion itself is a trade signal.

Choose among three event dates

The API's date can occur shortly after trading begins under the new symbol. A completion study should prefer closing_date when it is populated, while a price study should use trading_commencement_date for the first session. Keep the filing date as the first-known source clock and document fallbacks for null enriched dates.

The historical de-SPAC completion API guide covers the request mechanics. This workflow adds the explicit clock hierarchy needed for event windows.

Pull completed events only

Date filters apply to the filing-date date field, and exact date cannot be combined with a range. Results arrive in descending date order without pagination. The route serves only rows labeled as de-SPAC completions and keeps one event record per event issuer in the response.

import os
import requests
import pandas as pd

response = requests.get(
    "https://api.alphanume.com/v1/de-spac-events",
    headers={"X-API-Key": os.environ["ALPHANUME_API_KEY"]},
    params={"date_gte": "2020-01-01", "date_lte": "2025-12-31"},
    timeout=30,
)
response.raise_for_status()
payload = response.json()
events = pd.DataFrame(payload["data"])

events["cohort_date"] = pd.to_datetime(events["closing_date"])
events["first_trade_date"] = pd.to_datetime(events["trading_commencement_date"])
events["filing_date"] = pd.to_datetime(events["date"])
events.to_parquet("despac_completion_clocks.parquet", index=False)

Do not silently fill a missing closing date with the filing date. Add a cohort_date_source column and label every fallback. That lets the primary analysis use supported completion dates while a sensitivity analysis includes filing-date proxies without mixing the two.

A live completion screen may first observe the transaction through the later closing disclosure even when closing_date says the legal event occurred earlier. Backtesting a same-day trade on the earlier date requires a separately timestamped source that was available then. The database date remains the conservative first-known clock for its own record.

Connect the old and new security

Pre-completion price history belongs to the shell, while post-completion history belongs to the operating company under the new symbol. A ticker-only merge can leave a gap or attach the wrong issuer. Save a bridge with old security identifier, new security identifier, closing date, and first trading date.

For an event study, begin returns on the first observed session under the new ticker and retain cases with missing prices. A company that later delists still belongs in the original cohort.

Null economics are unknown

• Redemptions. redemption_shares and redemption_amount_usd can be null when filings do not support them.
• Financing. A null pipe_amount_usd does not prove there was no PIPE.
• Transaction values. Enterprise and equity values come from deal documents and are not live market capitalization.
• Confidence. Extraction confidence is not completion probability or expected return.
• Scope. Because only completed deals appear, the database cannot estimate announcement-to-completion odds or terminated-deal outcomes.

Evidence quote and filing URL let you audit the completion label. Enriched values can come from several related filings, summarized by source_form_types and filing_count. Preserve the source fields when an economic variable drives a subgroup.

Create a clock-audited cohort

Pull one year and export every event with closing, first-trade, filing, and effective dates. Report null and conflicting clocks, build the old-to-new security bridge, and check a sample of completion evidence against the filing URL. Only then attach returns from the first trade under the new ticker.

Explore the fields on the De-SPAC Events page and use the De-SPAC Events guide for the complete dataset context. Full historical cohorts require more than the free trailing 20-session delayed window.