Business Insider on yesterday's decline:
...With little to raise alarm in the 
growth numbers and exchange rate, it's likely market-specific factors 
that explain the bulk of Monday's drop. In particular, a six-month ban on share sales by major investors, introduced on July 8, may come to an end this week. The result could be a significant volume of sell orders as six months of pent up pessimism are released.
 In addition, the market in December may have been artificially boosted 
by mutual funds as they attempted to bolster annual returns. Those 
artificial gains are now being wiped out....