When do US sanctions on Iran move a share price?
COSCO Shipping Energy, 2019: tanker units sanctioned
Short answer: the US warned the industry two months earlier, but nothing public named COSCO. The shares rose 7% beforehand.
What happened
- The action: on 2019-09-25 the US sanctioned COSCO Shipping Tanker (Dalian) and its ship-management arm for carrying Iranian oil (State Department release). Tankers are COSCO Shipping Energy’s main business.
- Afterwards: the US lifted these sanctions in January 2020 (Wikipedia, sourced).
Warning signs before the action
- 2019-07-22: the US sanctioned the Chinese oil trader Zhuhai Zhenrong for buying Iranian oil after China’s exemption ended in May 2019 (State Department release). This showed the US would now sanction Chinese companies in the Iranian oil trade.
- Naming COSCO: we found no public report or filing before 2019-09-25 that linked COSCO’s tankers to Iranian oil. We did not search ship-tracking reports from that time.
Share price before and after
- Before the action (against the local index): +6.8% over 60 trading days, −2.0% over 20, +0.6% over 5.
- After: −21.7% after 1 trading day, −26.2% after 5, −21.4% after 20.
What this shows
- A general warning didn’t move the price. The fall came only when the US named the company.
How we measured
- Share move: the company’s share price change minus the local index change, from daily closing prices (Yahoo Finance).
- Before: from the close 60, 20 and 5 trading days before the action, up to the last close before it.
- After: from that last close to 1, 5 and 20 trading days later.
- Data and code: case_study_summary.csv, case_study_price_paths.csv, scripts/case_studies.py.
- Saved sources: receipts/case-studies.