On Monday evening, around 6:00 PM Eastern Standard Time, news leaked that the United States District Court for the Southern District of New York had decided to allow the T-Mobile/Sprint merger to go through, giving the companies a victory over a group of state attorneys general trying to block the deal.
Thomas Philippon, a professor of finance at NYU, used this opportunity to conduct a quick-and-dirty event study on Twitter:
Short thread on T-Mobile/Sprint merger. There were 2 theories:
(A) It’s a 4-to-3 merger that will lower competition and increase markups.
(B) The new merged entity will be able to take on the industry leaders AT&T and Verizon.
(A) and (B) make clear predictions. (A) predicts the merger is good news for AT&T and Verizon’s shareholders. (B) predicts the merger is bad news for AT&T and Verizon’s shareholders. The news leaked at 6pm that the judge would approve the merger. Sprint went up 60% as expected. Let’s test the theories.
Here is Verizon’s after trading price: Up 2.5%.
Here is ATT after hours: Up 2%.
Conclusion 1: Theory B is bogus, and the merger is a transfer of at least 2%*$280B (AT&T) + 2.5%*$240B (Verizon) = $11.6 billion from the pockets of consumers to the pockets of shareholders.
Conclusion 2: I and others have argued for a long time that theory B was bogus; this was anticipated. But lobbying is very effective indeed…
Conclusion 3: US consumers already pay two or three times more than those of other rich countries for their cell phone plans. The gap will only increase.
And just a reminder: these firms invest 0% of the excess profits.
Philippon published his thread about 40 minutes prior to markets opening for regular trading on Tuesday morning. The Court’s official decision was published shortly before markets opened as well. By the time regular trading began at 9:30 AM, Verizon had completely reversed its overnight increase and opened down from the previous day’s close. While AT&T opened up slightly, it too had given back most of its initial gains. By 11:00 AM, AT&T was also in the red. When markets closed at 4:00 PM on Tuesday, Verizon was down more than 2.5 percent and AT&T was down just under 0.5 percent.
Does this mean that, in fact, theory A is the “bogus” one? Was the T-Mobile/Sprint merger decision actually a transfer of “$7.4 billion from the pockets of shareholders to the pockets of consumers,” as I suggested in my own tongue-in-cheek thread later that day? In this post, I will look at the factors that go into conducting a proper event study.
What’s the appropriate window for a merger event study?
In a response to my thread, Philippon said, “I would argue that an event study is best done at the time of the event, not 16 hours after. Leak of merger approval 6 pm Monday. AT&T up 2 percent immediately. AT&T still up at open Tuesday. Then comes down at 10am.” I don’t disagree that “an event study is best done at the time of the event.” In this case, however, we need to consider two important details: When was the “event” exactly, and what were the conditions in the financial markets at that time?
This event did not begin and end with the leak on Monday night. The official announcement came Tuesday morning when the full text of the decision was published. This additional information answered a few questions for market participants:
- Were the initial news reports true?
- Based on the text of the decision, what is the likelihood it gets reversed on appeal?
- Wall Street: “Not all analysts are convinced this story is over just yet. In a note released immediately after the judge’s verdict, Nomura analyst Jeff Kvaal warned that ‘we expect the state AGs to appeal.’ RBC Capital analyst Jonathan Atkin noted that such an appeal, if filed, could delay closing of the merger by ‘an additional 4-5’ months — potentially delaying closure until September 2020.”
- Did the Court impose any further remedies or conditions on the merger?
As stock traders digested all the information from the decision, Verizon and AT&T quickly went negative. There is much debate in the academic literature about the appropriate window for event studies on mergers. But the range in question is always one of days or weeks — not a couple hours in after hours markets. A recent paper using the event study methodology analyzed roughly 5,000 mergers and found abnormal returns of about positive one percent for competitors in the relevant market following a merger announcement. Notably for our purposes, this small abnormal return builds in the first few days following a merger announcement and persists for up to 30 days, as shown in the chart below:
As with the other studies the paper cites in its literature review, this particular research design included a window of multiple weeks both before and after the event occured. When analyzing the T-Mobile/Sprint merger decision, we should similarly expand the window beyond just a few hours of after hours trading.
How liquid is the after hours market?
More important than the length of the window, however, is the relative liquidity of the market during that time. The after hours market is much thinner than the regular hours market and may not reflect all available information. For some rough numbers, let’s look at data from NASDAQ. For the last five after hours trading sessions, total volume was between 80 and 100 million shares. Let’s call it 90 million on average. By contrast, the total volume for the last five regular trading hours sessions was between 2 and 2.5 billion shares. Let’s call it 2.25 billion on average. So, the regular trading hours have roughly 25 times as much liquidity as the after hours market.
We could also look at relative liquidity for a single company as opposed to the total market. On Wednesday during regular hours (data is only available for the most recent day), 22.49 million shares of Verizon stock were traded. In after hours trading that same day, fewer than a million shares traded hands. You could change some assumptions and account for other differences in the after market and the regular market when analyzing the data above. But the conclusion remains the same: the regular market is at least an order of magnitude more liquid than the after hours market. This is incredibly important to keep in mind as we compare the after hours price changes (as reported by Philippon) to the price changes during regular trading hours.
What are Wall Street analysts saying about the decision?
To understand the fundamentals behind these stock moves, it’s useful to see what Wall Street analysts are saying about the merger decision. Prior to the ruling, analysts were already worried about Verizon’s ability to compete with the combined T-Mobile/Sprint entity in the short- and medium-term:
Last week analysts at LightShed Partners wrote that if Verizon wins most of the first available tranche of C-band spectrum, it could deploy 60 MHz in 2022 and see capacity and speed benefits starting in 2023.
“With that timeline, C-Band still does not answer the questions of what spectrum Verizon will be using for the next three years,” wrote LightShed’s Walter Piecyk and Joe Galone at the time.
Following the news of the decision, analysts were clear in delivering their own verdict on how the decision would affect Verizon:
“Verizon looks to us to be a net loser here,” wrote the MoffettNathanson team led by Craig Moffett.
“Approval of the T-Mobile/Sprint deal takes not just one but two spectrum options off the table,” wrote Moffett. “Sprint is now not a seller of 2.5 GHz spectrum, and Dish is not a seller of AWS-4. More than ever, Verizon must now bet on C-band.”
LightShed also pegged Tuesday’s merger ruling as a negative for Verizon.
“It’s not great news for Verizon, given that it removes Sprint and Dish’s spectrum as an alternative, created a new competitor in Dish, and has empowered T-Mobile with the tools to deliver a superior network experience to consumers,” wrote LightShed.
In a note following news reports that the court would side with T-Mobile and Sprint, New Street analyst Johnathan Chaplin wrote, “T-Mobile will be far more disruptive once they have access to Sprint’s spectrum than they have been until now.”
However, analysts were more sanguine about AT&T’s prospects:
AT&T, though, has been busy deploying additional spectrum, both as part of its FirstNet build and to support 5G rollouts. This has seen AT&T increase its amount of deployed spectrum by almost 60%, according to Moffett, which takes “some of the pressure off to respond to New T-Mobile.”
Still, while AT&T may be in a better position on the spectrum front compared to Verizon, it faces the “same competitive dynamics,” Moffett wrote. “For AT&T, the deal is probably a net neutral.”
The quantitative evidence from the stock market seems to agree with the qualitative analysis from the Wall Street research firms. Let’s look at the five-day window of trading from Monday morning to Friday (today). Unsurprisingly, Sprint, T-Mobile, and Dish have reacted very favorably to the news:
Consistent with the Wall Street analysis, Verizon stock remains down 2.5 percent over a five-day window while AT&T has been flat over the same period:
How do you separate beta from alpha in an event study?
Philippon argued that after market trading may be more efficient because it is dominated by hedge funds and includes less “noise trading.” In my opinion, the liquidity effect likely outweighs this factor. Also, it’s unclear why we should assume “smart money” is setting the price in the after hours market but not during regular trading when hedge funds are still active. Sophisticated professional traders often make easy profits by picking off panicked retail investors who only read the headlines. When you see a wild swing in the markets that moderates over time, the wild swing is probably the noise and the moderation is probably the signal.
And, as Karl Smith noted, since the aftermarket is thin, price moves in individual stocks might reflect changes in the broader stock market (“beta”) more than changes due to new company-specific information (“alpha”). Here are the last five days for e-mini S&P 500 futures, which track the broader market and are traded after hours:
The market trended up on Monday night and was flat on Tuesday. This slightly positive macro environment means we would need to adjust the returns downward for AT&T and Verizon. Of course, this is counter to Philippon’s conjecture that the merger decision would increase their stock prices. But to be clear, these changes are so minuscule in percentage terms, this adjustment wouldn’t make much of a difference in this case.
Lastly, let’s see what we can learn from a similar historical episode in the stock market.
The parallel to the 2016 presidential election
The type of reversal we saw in AT&T and Verizon is not unprecedented. Some commenters said the pattern reminded them of the market reaction to Trump’s election in 2016:
Much like the T-Mobile/Sprint merger news, the “event” in 2016 was not a single moment in time. It began around 9 PM Tuesday night when Trump started to overperform in early state results. Over the course of the next three hours, S&P 500 futures contracts fell about 5 percent — an enormous drop in such a short period of time. If Philippon had tried to estimate the “Trump effect” in the same manner he did the T-Mobile/Sprint case, he would have concluded that a Trump presidency would reduce aggregate future profits by about 5 percent relative to a Clinton presidency.
But, as you can see in the chart above, if we widen the aperture of the event study to include the hours past midnight, the story flips. Markets started to bounce back even before Trump took the stage to make his victory speech. The themes of his speech were widely regarded as reassuring for markets, which further pared losses from earlier in the night. When regular trading hours resumed on Wednesday, the markets decided a Trump presidency would be very good for certain sectors of the economy, particularly finance, energy, biotech, and private prisons. By the end of the day, the stock market finished up about a percentage point from where it closed prior to the election — near all time highs.
Maybe this is more noise than signal?
As a few others pointed out, these relatively small moves in AT&T and Verizon (less than 3 percent in either direction) may just be noise. That’s certainly possible given the magnitude of the changes. Contra Philippon, I think the methodology in question is too weak to rule out the pro-competitive theory of the case, i.e., that the new merged entity would be a stronger competitor to take on industry leaders AT&T and Verizon. We need much more robust and varied evidence before we can call anything “bogus.” Of course, that means this event study is not sufficient to prove the pro-competitive theory of the case, either.
Olivier Blanchard, a former chief economist of the IMF, shared Philippon’s thread on Twitter and added this comment above: “The beauty of the argument. Simple hypothesis, simple test, clear conclusion.”
If only things were so simple.