Finder UK
UK
AU
US
NZ
CA
SG
More

The effects of controversies on share prices

A rogue tweet can have a major impact

Charlie Barton
Charlie Barton

Updated

Fact checked
Picture not described

Share prices fluctuate every day, and are particularly prone to change when the company concerned features in the news. We studied some particularly noteworthy instances of this, to demonstrate how a single event, and public perception, can have a major effect on a company’s value.

The best and the worst

The most dramatic drop belongs to BP, thanks to its disastrous oil spill in 2010. Its share price dropped by 20%, decreasing its total value by £14 billion.

BP share price before and after the oil spill

Date BP share price
2010-04-13 640.7
2010-04-14 643.1
2010-04-15 653
2010-04-16 641.8
2010-04-19 642.5
2010-04-20 Day of event! 655.4
2010-04-21 648.2
2010-04-22 636.4
2010-04-23 639.7
2010-04-26 626.8
2010-04-27 610
2010-04-28 625
2010-04-29 584.2
2010-04-30 575.5
2010-05-04 558.5
2010-05-05 565
2010-05-06 567
2010-05-07 553.9
2010-05-10 549.2
2010-05-11 545.5
2010-05-12 541.6
2010-05-13 547.6
2010-05-14 530.2
2010-05-17 529.9
2010-05-18 534
2010-05-19 523.5
2010-05-20 528.8
2010-05-21 506.7
2010-05-24 493
2010-05-25 485.2
2010-05-26 492
2010-05-27 520.8
2010-05-28 494.8
2010-06-01 430
2010-06-02 429.75
2010-06-03 432.25
2010-06-04 433.35
2010-06-07 430.3
2010-06-08 408.9
2010-06-09 391.55
2010-06-10 365.5
2010-06-11 391.9
2010-06-14 355.45
2010-06-15 342
2010-06-16 337
2010-06-17 359.7
2010-06-18 357.45
2010-06-21 349.5
2010-06-22 334.2
2010-06-23 333.5
2010-06-24 325.25
2010-06-25 304.6
2010-06-28 308.25
Before the oil spill, BP’s share price was fluctuating around 650 GBp(Great British pence). In the months that followed, this price decreased steadily, reaching a low of 304.6p. Since then, the price has recovered significantly, sitting at 546p.

.

Weight Watchers’ share price before and after Oprah Winfrey’s Golden Globe speech

Date Weightwatchers share price
2017-12-14 45.33
2017-12-15 45.34
2017-12-18 47.02
2017-12-19 45.85
2017-12-20 46.77
2017-12-21 47.45
2017-12-22 50.52
2017-12-26 48.79
2017-12-27 49.35
2017-12-28 47.38
2017-12-29 44.28
2018-01-02 47.83
2018-01-03 47.18
2018-01-04 46.7
2018-01-05 Day of event! 46.91
2018-01-08 52.62
2018-01-09 57.37
2018-01-10 56.89
2018-01-11 56.98
2018-01-12 59.44
2018-01-16 59.21
2018-01-17 61.84
2018-01-18 61.19
2018-01-19 63.5
2018-01-22 64.86
2018-01-23 67.7
2018-01-24 67.34

The biggest rise in our analysis occurred in thanks to Oprah Winfrey, a shareholder and icon of Weight Watchers. Her January 2018 speech at the Golden Globes awards increased the value of Weight Watchers’ shares by 14%, from US$46.91 to $52.62. Since then, Weight Watchers’ shares have risen higher still, to $64.52.

Other drops in share price

Tesla share price before and after Elon Musk’s emotional interview

Date Tesla share price
2018-08-07 379.57
2018-08-08 370.34
2018-08-09 352.45
2018-08-10 355.49
2018-08-13 356.41
2018-08-14 347.64
2018-08-15 338.69
2018-08-16 Day of event! 335.45
2018-08-17 305.5
2018-08-20 308.44
2018-08-21 321.9
2018-08-22 321.64
2018-08-23 320.1

Event: In August 2018, an interview with Elon Musk caused Tesla share prices to drop by 9%, after he divulged the details of his “excruciating” year.

Source: The Express

Juventus shares before and after Cristiano Ronaldo’s rape allegation

Date Juventus share price
2018-09-24 1.54
2018-09-25 1.53
2018-09-26 1.54
2018-09-27 1.52
2018-09-28 1.47
2018-10-01 1.47
2018-10-02 Day of event! 1.45
2018-10-03 1.33
2018-10-04 1.32
2018-10-05 1.19
2018-10-08 1.14
2018-10-09 1.14
2018-10-10 1.07
2018-10-11 1.09
2018-10-12 1.03
2018-10-15 1.07
2018-10-16 1.15
2018-10-17 1.05
2018-10-18 1.05
2018-10-19 1.01

Event: Cristiano Ronaldo accused of rape, which he denies

Source: BBC news

Facebook shares before and after it announces revenue growth rate decline

Date Facebook share price
2018-07-16 207.23
2018-07-17 209.99
2018-07-18 209.36
2018-07-19 208.09
2018-07-20 209.94
2018-07-23 210.91
2018-07-24 214.67
2018-07-25 Day of event! 217.5
2018-07-26 176.26
2018-07-27 174.89
2018-07-30 171.06
2018-07-31 172.58
2018-08-01 171.65

Event: Facebook announced revenue growth rates will continue to decelerate.

Source: The Guardian

Facebook before and after the Cambridge Analytica data compromise story

Date Facebook share price
2018-03-07 183.71
2018-03-08 182.34
2018-03-09 185.23
2018-03-12 184.76
2018-03-13 181.88
2018-03-14 184.19
2018-03-15 183.86
2018-03-16 Day of event! 185.09
2018-03-19 172.56
2018-03-20 168.15
2018-03-21 169.39
2018-03-22 164.89
2018-03-23 159.39
2018-03-26 160.06
2018-03-27 152.22

Event: Facebook stock value plunges after it’s revealed that 50 million people may have had data compromised by Cambridge Analytica.

Source: CBS News

Snapchat shares after Kylie Jenner announces Snapchat is dead

Date Snapchat share price
2018-02-07 20.75
2018-02-08 19.39
2018-02-09 18.8
2018-02-12 18.63
2018-02-13 18.58
2018-02-14 19.56
2018-02-15 19.75
2018-02-16 20.42
2018-02-20 18.93
2018-02-21 Day of event! 18.64
2018-02-22 17.51
2018-02-23 17.45
2018-02-26 17.09
2018-02-27 16.32
2018-02-28 17.32

Event: Snapchat declared dead on 21 February 2018 by Kylie Jenner.

Source: The Verge

Toyota share prices before and after a President Trump tweet

Date Toyota share price
2017-01-03 118.55
2017-01-04 121.19
2017-01-05 Day of event! 120.44
2017-01-06 120.13
2017-01-09 119.74
2017-01-10 119.76
2017-01-11 119.91
2017-01-12 119.64
2017-01-13 119.81
2017-01-17 118.41
2017-01-18 118.79
2017-01-19 119.31
2017-01-20 118.92
2017-01-23 118.29
2017-01-24 117.64
2017-01-25 119.06
2017-01-26 118.98
2017-01-27 116.69
2017-01-30 116.07
2017-01-31 115.75
2017-02-01 115.26
2017-02-02 114.53
2017-02-03 115.12
2017-02-06 113.31
2017-02-07 113.04
2017-02-08 113.27
2017-02-09 111.92

Event: US president Donald Trump tweets “Toyota Motor said will build a new plant in Baja, Mexico, to build Corolla cars for U.S. NO WAY! Build plant in U.S. or pay big border tax.”

Source: The Independent

Amazon shares before and after another President Trump tweet

Date Amazon share price
2018-03-14 1591
2018-03-15 1582.32
2018-03-16 1571.68
2018-03-19 1544.93
2018-03-20 1586.51
2018-03-21 1581.86
2018-03-22 1544.92
2018-03-23 1495.56
2018-03-26 1555.86
2018-03-27 1497.05
2018-03-28 1431.42
2018-03-29 1447.34
2018-04-02 1371.99
2018-04-03 1392.05
2018-04-04 1410.57
2018-04-05 1451.75
2018-04-06 1405.23

Event: US president Donald Trump tweets “It is reported that the U.S. Post Office will lose $1.50 on average for each package it delivers for Amazon. That amounts to billions of dollars.”

Source: Medium

Share price increases

Apple shares after it becomes the first US company to be worth $1 trillion

Date Apple share price
2018-07-18 190.4
2018-07-19 191.88
2018-07-20 191.44
2018-07-23 191.61
2018-07-24 193
2018-07-25 194.82
2018-07-26 194.21
2018-07-27 190.98
2018-07-30 189.91
2018-07-31 Day of event! 190.29
2018-08-01 201.5
2018-08-02 207.39
2018-08-03 207.99
2018-08-06 209.07
2018-08-07 207.11
2018-08-08 207.25
2018-08-09 208.88
2018-08-10 207.53
2018-08-13 208.87
2018-08-14 209.75

Event: Apple became world’s first trillion-dollar company

Source: The Guardian

Nike before and after its Colin Kaepernick advert

Date Nike Share Price
2018-08-21 82.02
2018-08-22 82.28
2018-08-23 82.34
2018-08-24 82.1
2018-08-27 82.23
2018-08-28 82.48
2018-08-29 82.22
2018-08-30 81.01
2018-08-31 Day of event! 82.2
2018-09-04 79.6
2018-09-05 79.92
2018-09-06 80.4
2018-09-07 80.3
2018-09-10 82.1
2018-09-11 82.63
2018-09-12 83
2018-09-13 83.47
2018-09-14 83.49
2018-09-17 83.26
2018-09-18 85.26

Event: Nike shares dropped, then rose to higher than before, after Colin Kaepernick became the new face of its “Just Do It” ads.

Source: Markets Insider

Apple shares before and after a Carl Icahn tweet

Date Apple
2013-07-31 64.65
2013-08-01 65.24
2013-08-02 66.08
2013-08-05 67.06
2013-08-06 66.46
2013-08-07 66.43
2013-08-08 65.86
2013-08-09 64.92
2013-08-12 Day of event! 66.77
2013-08-13 69.94
2013-08-14 71.21
2013-08-15 71.13
2013-08-16 71.76
2013-08-19 72.53
2013-08-20 71.58
2013-08-21 71.77
2013-08-22 71.85

Event: Carl Icahn tweeted “We currently have a large position in APPLE. We believe the company to be extremely undervalued. Spoke to Tim Cook today. More to come.”

Source: Financial Post

Click here for more research. For all media enquiries, please contact:

Matt Mckenna
UK Communications Manager
T: +44 20 8191 8806
matt.mckenna@finder.com@MichHutchison/in/matthewmckenna2

Related articles

More guides on finder

Ask an Expert

You are about to post a question on finder.com:

  • Do not enter personal information (eg. surname, phone number, bank details) as your question will be made public
  • finder.com is a financial comparison and information service, not a bank or product provider
  • We cannot provide you with personal advice or recommendations
  • Your answer might already be waiting – check previous questions below to see if yours has already been asked

Finder.com provides guides and information on a range of products and services. Because our content is not financial advice, we suggest talking with a professional before you make any decision.

By submitting your comment or question, you agree to our Privacy and Cookies Policy and Terms of Use.

Questions and responses on finder.com are not provided, paid for or otherwise endorsed by any bank or brand. These banks and brands are not responsible for ensuring that comments are answered or accurate.
Go to site