The Comparison
This strategy involves Global X Silver Miners ETF (NYSE:SIL) that tracks a basket of silver mining stocks.
Strategy
1. Buying ticker SIL at the close of trading each trading day and
2. selling at the next open.
*Strategy B – for comparisons sake – involves:
1. Buying ticker SIL at the open of trading each trading day and
2. selling at the close.
For the first test we simply:
*Subtract yesterday’s close price from today’s open price and keep a running total of the gain or loss (see the blue line in Figure 1)
*Subtract today’s open price from today’s close price and keep a running total of the gain or loss (See the red line in Figure 1)
Figure 1 – Raw $ per share gain (loss) for ticker SIL from holding a long position overnight (blue line) versus holding a long position between open and close (red line); 4/20/2010 to 11/14/2016
There clearly appears to be a positive bias to the “overnight” period (i.e., from the previous day’s close to the next day’s open) and a decidedly negative bias to the “daytime” period (i.e., from the open to the close each day).
Results
Let’s look at the same data a different way.
Since closing at $44.26 on its first day of trading on 4/20/2010:
*iShares Silver (NYSE:SLV) has lost -$9.04 a share (closing at $35.22 on 11/14/2016)
*The cumulative gain from each day’s close to the next day’s open was $136.31
*The cumulative loss from each day’s open to the close of the day was (-$145.35)
See Figure 2
Figure 2 – SIL shares have lost -$9.04 since inception (green line). Lots of gain overnight (blue line); lots of loss intraday (red line)
Summary
I can’t say for sure if there is a tradable edge to holding silver stocks overnight. But I will say this – if you are planning to trade SIL, I urge you to play the short side of the market.