Like Australia, many global equity markets have taken a turn downwards, with the falls in the markets closely linked to the rise of the US Dollar.  However, the S&P500 and Nikkei 225 have bucked this trend to hold up pretty well during September. 
The USD has been rallying due to the out-of-sync monetary policies with Japan and Europe. The US is expected to cease its Quantitative Easing program in October and likely to start raising rates by June next year, after seven years of zero rates.
Europe, however, will ramp up monetary loosening in October with the expectation that a “full-blown” QE program will need to follow in 2015. This is because deflationary risks persist in Eurpe and the appetite by banks to lend is low.
Recent inflation figures for Japan are in line with BoJ expectations although weaker than the market anticipated. The October BoJ meeting is unlikely to result in further QE measures due to the fall in the YEN. If inflation does not pick up in the last quarter of this year then we are likely to see an increase in QE for Japan.
In Australia unless we see a pickup in inflation and a fall in unemployment, the RBA will keep rates on hold for the foreseeable future. The main reason being to assist the transition of the Australian economy from mining investment to construction.
The four reason why we think the Australian equity market has fallen in September are:

1. The AUD weakness against the USD - we need this to stabilise to attract foreign investors back into the market and for Australian investors to begin buying;
2. The Australian market is very concentrated in the financial and resources sector - these 2 sectors have recently underperformed globally
3. Liquidity concerns around interest rates rising in the US is causing a similar sell off as the “tapper tantrums” did last June.
4. Portfolio concentration – holding bank stocks has been a crowded and profitable trade with many investors being overweight banks.  This has amplified the selloff in banks when investors have decided to take profits and exit.

September has also been a bad month for emerging market equities.  We don't expect the sell-off to turn into a full surrender. The impact of higher US interest rates on EM equities as a whole is likely to be quite limited. Today, most EM countries have lower external financing requirements; more foreign exchange reserves than they did two decades ago; and floating exchange rates. We also expect the Fed to raise rates slowly, not abruptly as it has on other occasions, which should help cushion the impact.