One of the stranger theories I have seen is that it is based on Astrology as there is a confluence of Uranus squaring the lunar nodes... whatever that means. There is a saying supposedly attributed to JP Morgan (but not likely) "Millionaires don't use astrology but Billionaires do."

One of the more rational ideas I have seen of any kind of divination is that it provides a means of passing judgement over to a near seemingly random system. If you are reading tea leaves, doing an 'I Ching' divination, biobliomancy etc. that essentially provides a coin flip to make you go 'yes' or 'no' to an opportunity.