Rotman Management Magazine

Can Twitter Help Predict Firm Value?

Aggregatin­g stock informatio­n from tweets might allow investors to tap into the wisdom of crowds.

- By Partha Mohanram

New research shows that aggregatin­g stock-related informatio­n from Twitter can enable investors to tap into the ‘wisdom of the crowd’.

on informatio­n intermedia­ries — INVESTORS HAVE LONG RELIED from financial analysts and advisors to the business press, credit rating agencies, short sellers and auditors — to acquire timely and value-relevant informatio­n regarding the prospects of stocks. However, the past decade has witnessed an explosion in new sources of informatio­n that are easily accessible to capital market participan­ts.

With the rise of the Internet, individual investors are increasing­ly relying on each other as peer-to-peer sources of informatio­n. The early days of the Internet saw the rise of financial websites such as Yahoo! Finance, Motley Fool and Raging Bull. More recently, individual investors have shared informatio­n and opinion through portals such as Seekingalp­ha. However, by far, the biggest revolution in the disseminat­ion of informatio­n on the Internet has been the advent of social media platforms such as Twitter, which allow users to instantane­ously post their views about stocks to a wide audience.

While Twitter is undoubtedl­y an exciting and emerging new source of informatio­n for the capital markets, it is unclear whether it is actually useful to investors. As Twitter is an unregulate­d platform with potentiall­y anonymous users, the informatio­n in tweets may be uninformat­ive or even intentiona­lly misleading. For example, in two days in January 2013, a series of damning but false tweets on two stocks — Audience Inc. (ticker symbol: ADNC) and Sarepta Therapeuti­cs, Inc. (ticker symbol: SRPT) — sent their prices plunging by 28 per cent and 16 per cent, respective­ly.

Even though informatio­n from Twitter might be uninformat­ive or worse, misleading, there are also many reasons why it might actually prove to be a treasure trove of timely and relevant informatio­n for the capital markets. The main driver for this is a concept many readers will be familiar with: The Wisdom of Crowds.

The Wisdom of Crowds

The Wisdom of Crowds concept goes back over a century and refers to the phenomenon that the aggregatio­n of informatio­n provided by many individual­s often results in prediction­s that

are better than those made by any single member of the group, or even experts.

One classic example from the turn of the 20th century is Sir Francis Galton’s surprising finding that the crowd at a county fair accurately predicted the weight of an ox when their individual guesses were averaged. The crowd’s average (or median) prediction was closer to the ox’s true weight than the estimates of most crowd members, and even closer than any of the estimates made by cattle experts. Similarly, trial by jury can be understood as a manifestat­ion of the wisdom of crowds, especially when compared to trial by a single expert (i.e. a judge).

The principle of the wisdom of crowds has been validated by the ability of the Iowa Electronic Markets to predict election results with little or no bias. In fact, its prediction­s for highprofil­e elections outperform polls conducted by experts. Recent academic papers that build on the wisdom of crowds show that user-generated research reports and commentari­es posted on the Seekingalp­ha portal help predict stock returns and that Twitter informatio­n can predict future returns around Federal Open Market Committee (FOMC) meetings.

Aggregatin­g stock informatio­n from tweets might therefore allow one to tap into the wisdom of crowds. Twitter has two features that make it an attractive source and conduit of informatio­n: Its users come from diverse background­s and they are truly independen­t. Hence, in contrast to traditiona­l informatio­n intermedia­ries and other social media platforms (e.g., blogs, investing portals), they are less likely to be subject to ‘herding’ behaviour. Finally, Twitter’s short format (140 characters, with a 280-character limit in testing phase) and ease of informatio­n search (due the use of ‘cashtags’ like $AAPL) make it an ideal medium for sharing opinions and informatio­n in a timely and succinct fashion.

Our Research

Previous research on the impact of Twitter on the capital markets has focused primarily on how companies are exploiting this new channel to communicat­e with investors. While some researcher­s have examined whether aggregate investor sentiment on Twitter predicts the overall stock market, my colleagues and I decided to focus our attention on a potentiall­y more intriguing question: Does firm-specific informatio­n from Twitter help predict a firm’s future earnings and stock returns?

In a recent paper published in the Accounting Review, Eli Bartov of NYU’S Stern School of Business, Lucile Faurel of Arizona State University and I explored three questions:

1. Does the aggregate opinion in individual tweets regarding a stock’s prospects predict its quarterly earnings?

This was a test of the ‘relevance’ of the informatio­n provided by Twitter. We hypothesiz­ed that the aggregatio­n of opinions provided in individual tweets may result in a more accurate estimate of forthcomin­g earnings than the opinions of analysts, because individual tweets reflect opinions of a large and diverse group of people making independen­t and timely assessment­s of a company’s future prospects. If the wisdom of crowds and the value of the diversity and independen­ce of Twitter users outweigh any concerns about the credibilit­y of informatio­n from Twitter, then the informatio­n should be relevant to capital markets.

2. Does the aggregate opinion in individual tweets regarding a stock’s prospects predict the stock price reaction to the firm’s earnings realizatio­ns?

While informatio­n from Twitter may be relevant for predicting earnings, this question examined whether that informatio­n is new to the markets and hence moves stock prices. If this

Two features make Twitter an attractive source and conduit of informatio­n: Its users come from diverse background­s, and they are truly independen­t.

informatio­n is indeed new, we hypothesiz­ed, then it should also have the power to move stock prices.

3. Is the ability of informatio­n from Twitter to predict future earnings stronger for firms in weaker informatio­n environmen­ts?

We posited that the incrementa­l impact of additional informatio­n from Twitter may mean a lot more for a firm with a weaker analyst following and press coverage, as opposed to a widely followed and covered firm.

To address these three questions, we analyzed a broad sample of tweets spanning a four-year period, from January 1, 2009 to December 31, 2012. Our sample only covered tweets providing informatio­n related to a stock’s prospects and value, written by individual­s in the nine-trading-day period leading up to the firm’s quarterly earnings announceme­nt. Our analysis focused on earnings announceme­nts because they are recurring, high impact corporate events that are scrutinize­d closely by capital market participan­ts.

We obtained complete historical Twitter data from GNIP, the first authorized reseller of Twitter data. The data consisted of the full archive of tweets with ‘cashtags’—stock symbols preceded by the dollar sign, such as $AAPL for Apple Inc. and $PEP for Pepsico Inc. In an effort to increase confidence that the tweets related to the firm financial performanc­e and value, we limited our sample to tweets with cashtags. Given our interest in the ability of tweets to predict earnings, we focused only on tweets made in the nine-trading-day period leading up to the earnings announceme­nt. This resulted in a sample of 998,495 tweets from 3,662 unique firms.

An important research design choice was how to measure aggregate Twitter opinion. To enhance the robustness of our results, we used two different approaches. The first was a machine learning approach for analyzing entire tweet phrases and classifyin­g them as being positive or negative in their tone. The second approach focused on vocabulary, classifyin­g words as positive or negative and then counting the number of positive versus negative words. Note that this was done at the individual tweet level. Our next step was to aggregate this to the firm level across all tweets. To do this, we averaged the opinion across all tweets for a given firm, giving greater weight to Twitter users with more followers. Surely, we felt, the opinion of a frequent Twitter user with 100,000 followers should mean more than an infrequent user with a handful of followers.

Our Findings

Our first question pertained to the ability of social media to predict quarterly earnings, and collective­ly, our results strongly suggest that the aggregate opinion from individual tweets does help to predict earnings.

Additional analysis provided some interestin­g insights. When we decomposed our sample into tweets that provided new informatio­n (e.g. ‘$TPLM red from entry looking to time add spot as small oils out of favour... still love this co’) and those that disseminat­ed existing informatio­n (e.g. ‘Triangle Petroleum Announces Fourth Quarter Fiscal Year 2012 Earnings and Conference Call $TPLM #oil #petrol #TFB #OIL http://t.co/gvjdsjth’), we found that both kinds of tweets have predictive value. This suggests that Twitter has a dual role, both as a source of new informatio­n coming from individual users and as a means of disseminat­ing existing informatio­n.

In addition, we found that tweets that directly deal with stock fundamenta­ls (e.g. ‘Seen the lines for the new Iphone X?

To manifest itself, the wisdom of crowds needs a non-trivial number of distinct users providing their insights.

I think $AAPL will kill revenue estimates’) are more likely to be informativ­e than general tweets (e.g. ‘I added more $AAPL in the 90’s today... developing’).

Our second research question pertained to whether the informatio­n from Twitter predicts future stock returns. Here too, we found a strong associatio­n between aggregate Twitter opinion and the announceme­nt period’s stock returns. This suggests that not only is aggregate Twitter opinion relevant, it is also incrementa­lly informativ­e.

Our third research question dealt with how the ability of Twitter to predict future earnings varies with the informatio­n environmen­t. We looked at three dimensions of informatio­n environmen­t — analyst following, institutio­nal investment and press coverage — and found that the ability of aggregate Twitter opinion to predict future earnings is much stronger for firms in weaker informatio­n environmen­ts. In such firms, the dual role of Twitter as both a new source of informatio­n and a new channel of disseminat­ion is particular­ly important.

Finally, one of the assumption­s underlying the wisdom of crowds is that the ‘crowd’ has enough participan­ts that the ‘noise’ in individual opinion is diversifie­d away, allowing the ‘truth’ to emerge. Consistent with this, we found that to manifest itself, the wisdom of crowds needs a non-trivial number of distinct users providing their insights in order for the informatio­n to be useful to the capital markets..

Implicatio­ns for Practition­ers

The dramatic increase in the use of social media in recent years has had a significan­t impact on the capital markets. Firms now regularly use social media to communicat­e with their investor base and, increasing­ly, individual investors use social media to ‘crowd-source’ informatio­n and insights about the prospects of particular stocks.

While a healthy skepticism regarding the value of informatio­n on Twitter is warranted, our results suggest that informatio­n aggregated from a number of users regarding a stock’s prospects

does provide timely and relevant informatio­n. Hence, Twitter is another embodiment of the wisdom of crowds and has a dual role as a source of new informatio­n as well as a vehicle for the disseminat­ion of existing informatio­n. As indicated, these roles become particular­ly salient for firms in weak informatio­n environmen­ts.

Our results have important implicatio­ns for the role social media plays in the investing community. While investing may be viewed as a non-cooperativ­e, zero-sum game, our results demonstrat­e that individual­s are using social media to share informatio­n regarding companies’ future prospects for their mutual benefit.

Our findings are also important for regulators. Skeptics argue that individual­s exploit social media by disseminat­ing misleading and speculativ­e informatio­n, and thus call for more regulation of it. However, we found that the wisdom of crowds and the value of diversity and independen­ce trump any concerns about the lack of credibilit­y of informatio­n on Twitter. Put simply, informatio­n in social media may actually help investors make good investment decisions.

Overall, our findings highlight the importance for capital market participan­ts to consider informatio­n on stocks from Twitter when assessing a stock’s future prospects and value.

Partha Mohanram is the CPA Ontario Professor of Financial Accounting, Director of the India Innovation Institute and Professor of Accounting at the Rotman School of Management. This article summarizes his paper, “Can Twitter Help Predict Firm-level Earnings and Stock Returns?”, co-authored with Eli Bartov of the Stern School of Business at New York University and Lucile Faurel of the W.P. Carey School of Business at Arizona State University. This paper is forthcomin­g in The Accounting Review and is available online.

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