With IL&FS getting closer to an absolute liquidity crunch and defaulting on its ICDs and CPs, the RBI has started tightening the vigilance on banks and other financial institutions. For starters, the RBI asked banks to be cautious about buying HFC bonds considering their exposure to IL&FS debt. IL&FS has outstanding debt to the tune of $12.5 billion and the market is rife with news that most of the HFCs have large exposure to IL&FS debt. Of course, the promoters of Indiabulls and DHFL have denied any exposure but the news refuses to go away. The mood was also sourced by a large Indian mutual fund selling DHFL bonds in the market at an above-market yield of almost 11%. That also took its toll on the markets.

There are limits to examining historical data too. Nassim Taleb cites the error of believing that the highest mountain you’ve seen is the tallest. It’s far more likely that the tallest mountain is one you haven’t seen yet. In the same way with market crashes, we can look at market declines over different geographies and time periods, but it does not mean that there is necessarily any sort of hard limit there.

The Commodity Futures Trading Commission (CFTC) investigation concluded that Sarao "was at least significantly responsible for the order imbalances" in the derivatives market which affected stock markets and exacerbated the flash crash.[10] Sarao began his alleged market manipulation in 2009 with commercially available trading software whose code he modified "so he could rapidly place and cancel orders automatically."[10] Traders Magazine journalist, John Bates, argued that blaming a 36-year-old small-time trader who worked from his parents' modest stucco house in suburban west London[10] for sparking a trillion-dollar stock market crash is a little bit like blaming lightning for starting a fire" and that the investigation was lengthened because regulators used "bicycles to try and catch Ferraris." Furthermore, he concluded that by April 2015, traders can still manipulate and impact markets in spite of regulators and banks' new, improved monitoring of automated trade systems.[3]
Second, given that the effect of tariffs is to make imported goods more expensive so as to reduce the amount of goods imported, China may retaliate by imposing its own tariffs. Who knows what those will be? Whatever the case, this will make US goods less attractive in Chinese markets, and US companies relying on sales in China will end up making less money.

Futures and options markets are hedging and risk transfer markets. The report references a series of bona fide hedging transactions, totaling 75,000 contracts, entered into by an institutional asset manager to hedge a portion of the risk in its $75 billion investment portfolio in response to global economic events and the fundamentally deteriorating market conditions that day. The 75,000 contracts represented 1.3% of the total E-Mini S&P 500 volume of 5.7 million contracts on May 6 and less than 9% of the volume during the time period in which the orders were executed. The prevailing market sentiment was evident well before these orders were placed, and the orders, as well as the manner in which they were entered, were both legitimate and consistent with market practices. These hedging orders were entered in relatively small quantities and in a manner designed to dynamically adapt to market liquidity by participating in a target percentage of 9% of the volume executed in the market. As a result of the significant volumes traded in the market, the hedge was completed in approximately twenty minutes, with more than half of the participant's volume executed as the market rallied—not as the market declined. Additionally, the aggregate size of this participant's orders was not known to other market participants.

Market crashes are far more common in our imagination than in reality. This is because they are vivid and scary events. Given our evolution, we are wired to worry about these sorts of vivid events. While, this may have been useful in helping us avoid getting eaten by tigers, it's less useful for rational, disciplined stock market investing. By thinking this topic through now, hopefully you're a little better prepared when the next crash hits.