(Bloomberg) -- The Bank of Japan’s surprise lack of exchange-traded fund buying on Monday despite a drop in shares is spurring speculation the bank will stop purchasing ETFs, to try to make the nation’s stock market healthier by boosting liquidity for traders and reducing price distortion.Most Read from BloombergOne of the Most Infamous Trades on Wall Street Is Roaring BackChina Has Never Canceled This Many Shipments of US WheatTech CEOs Are Addicted to Taking Needless RisksChinese Stocks Gain 2