Here is a fun passage from Arthur C. Clarke's Rama II fictional novel, published in 1989. It presents an arguably realistic crash scenario for our [real world] financial systems. Food for thought in the bitcoin economy or fiat economy both. We are incredibly dependent on computer financial databases.
In contrast, terrestrial affairs were dominated by the emerging world economic crisis. On May 1, 2134, three of the largest international banks announced that they were insolvent because of bad loans. Within two days a panic had spread around the world. The more than one billion home terminals with access to the global financial markets were used to dump individual portfolios of stocks and bonds. The communications load on the Global Network System (GNS) was immense. The data transfer machines were stretched far beyond their capabilities and design specifications. Data gridlock delayed transactions for minutes, then hours, contributing additional momentum to the panic.
By the end of a week two things were apparent—that over half of the world's stock value had been obliterated and that many individuals, large and small investors alike, who had used their credit options to the maximum, were now virtually penniless. The supporting data bases that kept track of personal bank accounts and automatically transferred money to cover margin calls were flashing disaster messages in almost 20 percent of the houses in the world.
In truth, however, the situation was much much worse. Only a small percentage of the transactions were actually clearing through all the supporting computers because the data rates in all directions were far beyond anything that had ever been anticipated. In computer language, the entire global financial system went into the "cycle slip" mode. Billions and billions of information transfers at lower priorities were postponed by the network of computers while the higher priority tasks were being serviced first.
The net result of these data delays was that in most cases individual electronic bank accounts were not properly debited, for hours or even days, to account for the mounting stock market losses, Once the individual investors realized what was occurring, they rushed to spend whatever was still showing in their balances before the computers completed all the transactions. By the time governments and financial institutions understood fully what was going on and acted to stop all this frenetic activity, it was too late. The confused system had crashed completely. To reconstruct what had happened required carefully dumping and interleaving the backup checkpoint files stored at a hundred or so remote centers around the world.
For over three weeks the electronic financial management system that governed all money transactions was inaccessible to everybody. Nobody knew how much money he had—or how much anyone else had. Since cash had long ago become obsolete, only eccentrics and collectors had enough bank notes to buy even a week's groceries. People began to barter for necessities. Pledges based on friendship and personal acquaintance enabled many people to survive temporarily. But the pain had only begun. Every time the international management organization that oversaw the global financial system would announce that they were going to try to come back on-line and would plead with people to stay off their terminals except for emergencies, their pleas would be ignored, processing requests would flood the system, and the computers would crash again.
It was only two more weeks before the scientists of the world agreed on an explanation for the additional brightness in the apparition of Halley's Comet. But it was over four months before people could count again on reliable data base information from the GNS. The cost to human society of the enduring chaos was incalculable. By the time normal electronic economic activity had been restored, the world was in a violent financial down-spin that would not bottom out until twelve years later. It would be well over fifty years before the Gross World Product would return to the heights reached before the Crash of 2134.