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ING gets index price spike

Could the post-LIBOR regulatory crackdown on banks exacerbate price movements when indices are rebalanced?

Late afternoon on Friday shares in Dutch bank ING jumped nearly 5% in heavy trading on the Euronext Amsterdam exchange.

ING Price Spike


Source: Yahoo Finance

The price spike has now been fully reversed. A 5.75% increase in ING’s share price on Friday has been followed by a 4.69% decline yesterday and a further 1.23% fall so far on Tuesday morning.

ING’s late-Friday price move seems related to the reconstitution of equity indices. Friday’s market close set the price at which ING’s shares entered two indices from STOXX—the Euro STOXX banks index and the STOXX Europe 600 Banks. The latter index is a popular one: it underlies several European equity sector ETFs and is reportedly used in many bilateral swap agreements.

Both STOXX and ING declined to comment on Friday’s share price movements.

Price movements in shares entering and exiting benchmarks are a well-known phenomenon, and an unsurprising one. Index changes mean unavoidable cash flows in a whole range of tracker products, including futures, swaps, ETFs and index funds, which other market traders can try to exploit.

STOXX announced the September constituent changes for its indices on August 26 and between August 25 and September 18 ING shares had already risen 8.43%, a not-uncommon price rise between the announcement date for an index addition and the date on which the addition becomes effective.

So why the unusual late-Friday action?

According to one trader I’ve spoken to, post-LIBOR restrictions by banks’ compliance departments on their traders’ index-related deals may be having the effect of forcing market participants into the end-of-day auctions on stock exchanges, which are used to set closing prices.

Previously, said the trader, bank dealers could pre-position their trading books for index changes. Now, he argued, after the LIBOR revelations banks are scared of being seen to exploit benchmark-related trading flows. Instead, he told me, they are now taking the most conservative option: trading at the actual price point at which the index change occurs, even if this leads to a less efficient execution.

Managers of index-tracking funds and financial products face a similar dilemma: place a trade in the closing auction and risk losing money (as anyone buying ING at Friday’s close would have done by Monday morning) or attempt to trade either pre- or post-close. Shunning the closing exchange auction may mean you avoid involvement in a crowded trade, but fund managers will incur tracking error if the fund’s execution price is significantly different from the price used by the benchmark calculator.

Rebalancing-related share price movements may be exacerbated by another factor, the trader told me: the widespread use of volume-weighted average price (VWAP) algorithms. VWAP algos automatically seek to trade when volumes are highest.

“The more volume in the closing auction, the more the VWAP will seek to execute there, leading to more volume in the auction, more VWAP execution….in other words, a feedback loop,” the trader told me.

Not everyone I’ve spoken to agrees with this explanation. The ING price spike could have been caused by someone realising late in the day that they were incorrectly positioned for the index change, or even by a mistake, other traders suggested.

As the volumes of money in tracker products increase, there’s more at stake when indices rebalance. It’s clear that these events involve a trade-off between transparency and making it difficult for those seeking to game index changes. But it would be ironic if, by making trades more crowded, measures taken to clean up the benchmark business had a detrimental effect on the efficiency of indices.