Tanker-rate assessments from early March are at the heart of a UK High Court case brought by Mercuria, which seeks to invalidate figures used in derivatives worth billions of dollars.
TD3C is the Baltic Exchange's principal tanker index. Commodity traders use it when valuing and hedging derivatives.
Mercuria bases its challenge on what it says was a steep decline in Hormuz traffic after the U.S.-Israeli conflict with Iran began, alongside Iran's claim that it had imposed a blockade there. On that basis, the trader argues the index should not have continued to be issued.
The Baltic Exchange says experienced brokers set the assessments and that some ships continued transiting Hormuz. It says temporary lulls in activity along a route can happen.
Mercuria first cited losses in the hundreds of millions of dollars, but later removed its claims for monetary losses. The exchange's lawyers warn that an outcome in Mercuria's favor could affect markets broadly and potentially require hundreds of trades to be unwound.
The hearing is scheduled to begin Monday, Oct. 26.
