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Abbott’s 2013 Split Explains the Apparent Yahoo Price Drop

Article Quant Q&A · Author: DavidYamanoha
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Summary

The document explains why Yahoo historical prices for Abbott Laboratories (ABT) appear to drop sharply between the end of 2012 and the start of 2013, even though the listed corporate actions show only dividends. The accepted answer identifies the event: Abbott separated its business, with the new AbbVie (ABBV) company beginning as a separate stock. The apparent discontinuity therefore reflects the corporate split rather than an ordinary market move or a conventional stock split.

This example shows why historical price data should be interpreted alongside corporate events. A corporate separation can change what a ticker represents and how price series compare across dates. The response is brief and points to an external explanation; it does not describe Yahoo’s adjustment methodology or establish whether the quoted prices are adjusted or unadjusted. Researchers using the series should verify the provider’s treatment of the distribution before calculating returns.

Key ideas

  • Abbott’s business separation created a new publicly traded company, AbbVie.
  • The apparent ABT price discontinuity around the start of 2013 is associated with that separation.
  • Dividend records alone do not capture every corporate event that can affect a historical price series.
  • Check a data provider’s corporate-action adjustments before comparing prices across a separation.

Tags

EquitiesUS marketsEvent-driven
Full text
# Yahoo OHLC data reflects nonexistant stock split


# Yahoo OHLC data reflects nonexistant stock split












Can anyone explain why the OHLC data I'm getting from yahoo appears to reflect stock splits during times when no significant corporate actions have occurred?

For example, I'm looking at ABT and yahoo shows a closing price jump between Dec 31 2012 and Jan 1 2013.

> 2012-12-31T00:00:00.000-08:00 65.5 2013-01-02T00:00:00.000-08:00 32.05

But between Oct 2012 and Mar 2013 (according to yahoo) these are the only corporate actions that occurred

> DIVIDEND, 20130111,0.140000 DIVIDEND, 20121011,0.244700 STARTDATE, 20121001 ENDDATE, 20130301

What caused this price jump?

## Answer by Louis Marascio (score 2, accepted)

https://quant.stackexchange.com/a/14525

They split the company into two: ABT and ABBV. http://www.forbes.com/sites/brucejapsen/2012/10/17/a-less-acquisitive-abbott-labs-will-split-in-two-come-january/

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This summary was written by Stratmill's research agent from the original; it is not a copy of the source.