FACTBOX-Silver margin changes by CME since 2009

May 10 (Reuters) - CME Group Inc (CME.O) raised margin
requirements for the 5,000-ounce silver futures <0#SI:> five times
over a two-week period by a total of about 84 percent.

The margin hikes, cited as one of the triggers for the
broad-based rout in the commodities complex last week, sparked a
slide in silver prices since touching a record high of $49.51 an
ounce on April 28.

Following are some details of the increase:

* CME, the world's largest commodities exchange, hiked margins
to $14,000 per contract from $12,000 effective May 5, and again to
$16,000 effective May 9. Prior to April 25, the margin stood at
$8,700 per contract. [ID:nN04107715]

* Margins are deposits paid by investors in futures markets,
where full payment is made when contracts mature, to an exchange
or clearing house to cover the risk of default by that investor
and typically are based on the largest most-likely daily market
move.

* Exchanges typically raise margins to mitigate risks as price
volatility in the market increases.

* However, margins can also be used as a tool to curb
speculative trading activity, particularly "hot money," by
reducing the number of positions a party can hold by leveraging a
particular amount of money.

For a list of historical silver margin changes by CME click:

r.reuters.com/wav49r

Following are the percentage changes in the COMEX 5000 silver
futures (Tier 1) maintenance margins since 2009 (in U.S. dollars
per contract).
EFFECTIVE DATE INITIAL MAINTENANCE PERCENTAGE
CHANGE
09 May 2011 $21,600 $16,000 14.3
05 May 2011 $18,900 $14,000 16.7
03 May 2011 $16,200 $12,000 11.6
29 April 2011 $14,513 $10,750 13.2
26 April 2011 $12,825 $9,500 9.2
25 March 2011 $11,745 $8,700 5.5
21 Jan. 2011 $11,138 $8,250 6.5
17 Dec. 2010 $10,463 $7,750 6.9
16 Nov. 2010 $9,788 $7,250 11.5
11 Nov. 2010 $8,775 $6,500 30.0
01 Oct. 2010 $6,750 $5,000 0.0
07 June 2010 $6,750 $5,000 17.7
30 April 2010 $5,738 $4,250 -15.0
02 March 2010 $6,750 $5,000 0.0
12 Feb. 2010 $6,750 $5,000 11.1
15 Dec. 2009 $6,075 $4,500 12.5
21 Aug. 2009 $5,400 $4,000 -33.3
26 June 2009 $8,100 $6,000 -14.3
28 May 2009 $9,450 $7,000 16.7
22 Jan. 2009 $8,100 $6,000 -6.3
08 Jan. 2009 $8,640 $6,400 --
(Reporting by Naveen Arul in Bangalore; Editing by Lisa
Shumaker)