Summary
Updated Aug 30, 2026
Tianchen Cai files SEC Form 4 reports at Horizon Space Acquisition II Corp. (HSPT). 1 SEC Form 4 filing on record, dated 17 June 2026.
Trading Pattern
InsiderAlpha's records for Tianchen Cai go back to 2026: 1 primary Form 4 filing, an average of 1.0 per year. No transaction on record carries a Rule 10b5-1 flag - the filings look discretionary rather than pre-scheduled, which makes their timing more informative as a signal.
Most Active Insiders Right Now
Tianchen Cai has no co-filers on record, so these are insiders with the largest open-market activity across the market in the last 90 days.
- PAULSON CO. INC. - $146.78M of AAMI open-market activity in the last 90 days
- Xiaodong Li - $146.73M of SE open-market activity in the last 90 days
- Trive Capital Holdings LLC - $145.83M of LYNX open-market activity in the last 90 days
- TPG GP A, LLC - $144.89M of LFST open-market activity in the last 90 days
- INNOVEX CO-INVEST FUND, L.P. - $143.55M of INVX open-market activity in the last 90 days
- Amberjack Capital Partners, L.P. - $143.55M of INVX open-market activity in the last 90 days
More Notable Insiders
Other corporate insiders with significant SEC Form 4 track records on InsiderAlpha:
Frequently Asked Questions
Who is Tianchen Cai?
Tianchen Cai is a corporate insider of Horizon Space Acquisition II Corp. (HSPT). InsiderAlpha holds 1 primary Form 4 filing for them, the earliest from 2026, updated as new SEC EDGAR filings are processed.
How many SEC Form 4 filings has Tianchen Cai submitted recently?
1 primary Form 4 filing in the last 90 days, covering 1 company.
Where can I see all of Tianchen Cai's SEC filings?
All Form 4 filings, transaction values, and 10b5-1 plan flags are listed on this page and updated in real time as new SEC EDGAR filings are processed.
Learn More
Follow Tianchen Cai and every insider like them
A free account opens the full scored daily plan and every past day, a watchlist for any ticker, and 3 months of price history on every company page. No card.
Free plan available · Paid plans start with a 7-day free trial