Why lot size changes for futures for different month

I dont know whether this situation was there before but i started noticing it now.

This is the details for ACC future stock
for this month(oct) the lot size is 125 and next month and next to next month its 375. Why this change? I always thought lot size are fixed.

whether changes in lot size is towards increasing direction or it can also decrease as well? eg from 375 back to 125

You can find the details here: http://www.thehindu.com/business/ns...ts-of-151-stocks-8-indices/article7522274.ece.

NSE circular for the same is here: http://nseindia.com/content/circulars/FAOP30449.pdf.

The contract size are very stable overall. Some changes take place when the value of stock increases or goes down. However presently NSE has increased the minimum value for future contract from 2 lakh to 5 lakh as such all contratcs barring a few which were already much higher than 5 lakhs have been changed. A few contracts lot size was reduced too.

I really don’t know how it will help small time investors; any way retail investors with small investments now definitely avoid futures because margin size has now increased way much larger. The futures which used to cost 30000 rs now cost around 70-80k. This also means high profit and high loss(high risk) that a small time investor like me cant afford.

SEBI, the know all Regulator thinks that the small investors are fools and cannot handle their finances themselves and increase in lot size will discourage them from Trading Futures!