What figures are you looking at? Just the Cents Per Unit?
Also, do you mean the market performed poorly? Or VAS performed poorly in replicating the market?
I do think it's pointless to follow quarterly returns too closely. There's too much variability across the financial year. But I thought I'd do a quick calculation for VAS for the past October to December Quarter 2017 as your disappointment at the last quarter piqued my curiosity.
Price
VAS closing price on 2nd Oct - $72.91
VAS closing price on 29 Dec - $77.81
On price, a gain of $4.90, or 6.7%. Pretty solid result.
Distribution
A distribution of 68.0989 cents per unit. Assuming we go off the 29 Dec closing price of $77.81, then that's a yield of 0.8%.
(Or a yield of 0.93% if you want to be cheeky and go off the 2 Oct closing price)
Total Return
6.7% capital growth + .08% income is a total return of 7.6% for one quarter.
Remembering that distributions and growth are quite variable across quarters. But I think that's pretty decent.
If every quarter was like this we'd be looking at a 30.4% return for the year. Which has happened in the past.
Benchmark
Comparing the performance of VAS to the benchmark ASX300
2 Oct - 5,655.476
29 Dec - 6,023.304
A gain of 367.828 points, or 6.5%. This does not include dividends. But assuming the ASX 300 has an average yield of about 3-4% per annum, then this suggests you can tack on about 1 per cent to allow for dividends, which makes a total return of 7.5%.
Which is what VAS returned for the same period.
Summary?
So I think both the market performed quite well, and VAS did really well in tracking the market. I've never tracked this data before and it's comforting to know that VAS is so well aligned. It's one thing to go off official Vanguard reports, it's nice to know that double checking their reports gives the same results.
Also, the Cents Per Unit for VAS at 0.8% for the quarter theoretically equates to about 3.2% per annum, which is what you'd expect for the ASX 300. Whether or not that's a good thing depends on your circumstances. Some people want big dividends, others would prefer to avoid the tax consequences.
So I think it's important to recognise that it's actually a pretty good result.
There will be quarters where performance will be strongly negative. Where unemployment increases, people start taking public transport more frequently, abandoning pets, stop going to restaurants and the economy contracts and you'll see a real decline in the market and dividends will come under pressure. But I think it's just as important to remain sanguine in these circumstances as it is now.
Hope this helps with the hurt!