True although it's not quite that simple. Most senators have less risky portfolios than the S&P 500 with lots of bond ETFs and the like, so that's not a perfect comparison. We're working on creating a risk-adjusted return measure to provide a more accurate comparison.

probably makes sense to use a few different metrics of information ratio vs $SPY, t-bills and a 60/40 portfolio.

Instead of just plotting S&P, they should divide by it to reject the common-mode signal.

They should actually regress senator returns against Ken French's research factors [1] and measure the statistical/economic significance of the intercept and the volatility of the residuals.

If I return 2% per year, but do so at 1% volatility and zero market exposure, then I can be a highly successful hedge fund after applying 10x leverage.

[1] https://mba.tuck.dartmouth.edu/pages/faculty/ken.french/data...

Yeah this will probably end up being one of our benchmarks -- it's commonly used in academic literature to measure abnormal returns.

Where does this signal come from in a time-sequence series? I looked up "common mode signal" and in EE it looks like line to line interference, or line to ground interference. Does the existence of this signal presume a Senate's portfolio performance is somehow coupled to some index fund performance (S&P in this case)?

The common-signal would just be the general stock market performance. S&P is one way to approximate "the market". The idea being that you want a plot to show you how well they're doing in terms of market performance, not in terms of absolute share price (which is kind of meaningless here). Otherwise every shock to the general market ends up getting rendered in every line in the plot which is pretty distracting and makes it hard to see what's going on.

I'm not entirely sure either but you could use some combination of dS/dt dI/dt where S is the senator and I is the market?

What is the partial derivative of a sitting US senator?

Their portfolio

And others have had 20% annualised returns which are ... questionable.

I hit 20% this year, that much can totally be explained by random chance.

Any particular person getting a 20% return is not suspicious. The question is whether the distribution of returns over all senators is suspicious.

Any person getting a 20% in some small number of trades is fine. An individual getting 20% over a long period and a wide range of trades is definitely suspicious.

Or a single person outperforming over a long time horizon.

When you have enough people trading over some period of time, someone will have consistently high returns.

questionable? they have inside knowledge

Looks like Mitch McConnell is doing well just following the benchmark (VFIAX: Vanguard 500 Index Admiral Fund)

It appears that the Senate Majority Leader is a Bogle follower. I can cheer that even if I don’t agree with all of his policies :)

The interface is misleading, put mitch in the search field by name and then you will see all his investments.

If the senators use this data and that argument to prove they didn’t make too much money or didn’t do anything wrong, then please remove all insider-trading laws. Right now, it only hurts the law abiding minority that accidentally makes a mistake

It's hard to accidentally insider trade and very hard to get prosecuted for accidental insider trading in the United States. Europe, maybe. But not the US.