EUR/CHF higher for fourth day. What's behind the bid?

EUR/CHF up 180 pips since Friday's low

The euro is threatening the highest levels since March against the Swiss franc. The displeasure of the Swiss National Bank with the strong franc is no secret but there aren't any clear signs of intervention.

When they've bought euros over the past two months, it was usually swift and strong. The move over the past week has been gradual.

What else could it be?

1) The euro is broadly higher this week after bottoming at 1.0808 on Monday.

2) Greek worries have ebbed and safe-haven funds could be finding their way out of Switzerland