"It is becoming increasingly clear to us that the level of yields at which credit expansion in Europe and Japan will pick up in earnest is probably negative, and substantially so. Therefore, the ECB and BoJ should move more strongly toward penalizing savings via negative retail deposit rates or perhaps wealth taxes. With this stick would also come a carrot – for example, negative mortgage rates."
"As IB warns its FX traders, starting Monday, Interactive Brokers "will move to a credit interest policy which allows for negative rates on long cash balances held in JPY where accounts with balances over approximately 100 thousand USD will be subject to the current Benchmark Rate minus 0.25%."