Why do markets still fluctuate? What happens today

Markets still under pressure today.
U.S.
stock futures rose, after Treasury bonds steadied following a volatile session on Monday.
Oil gained ground as traders monitored developments in the war between Israel and Hamas.
Most Chinese stock indicators rose after the nation's sovereign wealth fund bought exchange-traded funds to support prices.
Asian shares were mixed, with markets in Japan and South Korea reversing declines of more than 1% to trade higher.
Quarterly earnings from US giants, a major economic calendar and anxiety over the war between Israel and Hamas are likely to keep investors on edge as Europe prepares to begin trading, with bitcoin prices hitting an 18-year high months.
What's happening in the markets today.
Why there is still nervousness The market spotlight has turned on cryptocurrencies today.
Bitcoin hit $35,000 for the first time since May last year, extending a rally fueled by expectations of renewed demand from exchange-traded funds.
Oil rose in Asian trade after falling from a high since Hamas' attack on Israel, while Tel Aviv was seen holding off an invasion of Gaza during hostage negotiations, containing the conflict for now.
There are growing calls within the country to reconsider the scope of a ground invasion of Gaza.
China reiterated that Israel must protect civilians even if it has the right to defend itself in a conflict.
In Japan, the central bank announced an unscheduled bond-buying operation on Tuesday, underscoring its desire to curb the speed of rises in sovereign yields.
The Topix benchmark rebounded after falling to its lowest since June.
Nidec, a key supplier to the technology and electric vehicle sectors, fell more than 10% on disappointing quarterly earnings.
Elsewhere, billionaire investor Bill Ackman wrote in a social media post that he liquidated his bet against US government bonds amid rising global risks.
Bill Gross, co-founder of Pacific Investment Management Co., wrote that he is buying short-term interest rate futures in anticipation of a recession later this year.
Investors' attention today is focused on the flash PMIs of Great Britain, France, the euro zone and the United States, which will provide clues on the economic picture ahead of the central bank meetings that will begin with the ECB's turn on Thursday 26 October.
On the quarterly front, tech leaders Microsoft and Google's parent company Alphabet will report earnings today.
In Europe, investors are closely watching the outgoing accounts of Barclays and French luxury group Kering, which will reveal whether it faced a slowdown in demand in the third quarter like its rival LVMH.