A nationwide case-crossover study in China, which examined more than 12 million deaths between 2013 and 2019, revealed that stock market volatility, including daily stock returns and intra-daily stock oscillations, was associated with heightened risks of mortality related to major adverse cardiovascular events and suicide. The study found that risks were present on the day of stock market volatility and the following day.
In the study, published in Engineering, researchers utilized data from the China Cause of Death Reporting System, covering all county-level units in mainland China. They investigated the impact of daily stock returns and intra-daily stock oscillations on mortality from acute myocardial infarction, hemorrhagic stroke, ischemic stroke, and suicide. The researchers examined a total of 12.6 million deaths, including 4.5 million deaths from acute myocardial infarction, 4.1 million deaths from hemorrhagic stroke, 3.2 million deaths from ischemic stroke, and 440,777 deaths from suicide.
More than half of the major adverse cardiovascular events (MACE)-related deaths (n = 6.5 million) occurred in individuals over 75 years of age, whereas more of the suicide deaths occurred in individuals aged 18 to 65 years. There were more deaths in males for all cause-specific mortality categories (55.2% for acute myocardial infarction, 58.5% for hemorrhagic stroke, 54.9% for ischemic stroke, and 58.5% for suicide).
The researchers investigated three stock indices: Shanghai Stock Exchange Composite Index, Shenzhen Stock Exchange Composite Index, and Shanghai and Shenzhen 300 Index (CSI 300). The associations between stock volatility and mortality were largely consistent across all three.
A 1% decrease in daily returns of the CSI 300 was associated with a 0.74% to 1.04% and 1.77% increase in the risk of MACE- and suicide-related mortality, respectively. Similarly, a 1% increase in daily returns was linked to a 0.57% to 0.85% and 0.92% increase in the mortality risks of MACE and suicide. A 1% increase in intra-daily stock oscillations was associated with a 0.67% to 0.77% and 1.09% increase in the mortality risks of MACE and suicide. The excess mortality risks were observed on the current day (lag 0 d), remained for 2 days, and were greatest for suicide and hemorrhagic stroke.
The researchers observed U-shaped associations between daily stock returns and mortality from MACE, with both stock rises and falls significantly increasing the risk. For suicide mortality, there was an inverted J-shaped curve, indicating a greater risk for stock falls than rises. The study also identified thresholds of stock market volatility significantly linked to mortality risks, with the CSI 300 thresholds being –1.73% to –2.56% for stock falls and 1.13% to 1.59% for stock rises in relation to MACE risk, and 3.3% for intra-daily stock oscillations in relation to suicide risk.
Stratified analyses revealed that the excess mortality risks were more pronounced among individuals aged 65 to 74 years, males, and those with lower education levels. The risks were also more significant during the cool season when considering intra-daily stock oscillations.
The study included deaths from rheumatic heart disease and myocardial disease as negative controls and found no significant associations between stock volatility indicators and mortality from these causes. Sensitivity analyses, which additionally controlled for daily fine particulate matter concentrations and weather conditions as well as deaths caused by undetermined intent, revealed minimal alterations in the primary estimates.
Disclosures were not made available at time of publishing.
