Has it been clarified why they all wanted their cash?
most important thing to realize here is that signature, silvergate, silicone valley bank all did everything right. they are exactly in compliance https://www.zerohedge.com/markets/silicon-valley-bank-followed-exactly-what-regulation-recommended
the only difference from others is their customers needed cash
Discussion
not officially but we know why silvergate customers wanted it.
silicon valley bank has many companies with declining revenue pulling down cash reserves and i do not know much about signature bank but i imagine many of their customers are having increased need to spend more money on higher devices and are drawing down reserves