Often, it doesn’t take any one single event to trigger a...

Often, it doesn’t take any one single event to trigger a re-rating. It just happens. Just like market corrections. Take for instance, the early February drop in world markets. What caused it? The cumulative run up of the previous few years without a decent correction, while in itself not a cause, certainly was a contributing factor.
It this case, it might be a slight shift out of banks into telcos. Or not. We’ll never know.