There are many things to like about this.
1. Owner operator
2. Big runway
3. low cost provider
4. competitors with legacy structure they cant move away from
5. cost plus business model focused on profitable clients
6. Loyal customers like me who really swear by the products advantages over competitors
7. Operating Leverage with no financial leverage.
I will admit not chasing this stock has been a mistake personally. I have always wanted it a few dollars lower and it keeps going up. It has been on my radar for a long time, but till now it has been a mistake of omission.
I will however play a little devils advocate and bring up a concern of mine. This has mainly to do with brokerage business in general rather than IB specific.
The recent trend has been to index funds and ETFs away from single stock picking. Most retail investors/traders are moving to low cost index providers and I believe this trend will only continue to strengthen, as frankly it is an intelligent way to operate for 99% of the investors in the long run.
The more recent trend among younger investors has been towards robo advisors like Betterment, Wealthfront and even Charles Schwab getting into it. these guys typically invest in ETFs etc and provide an easy to manage service for the average retail crowd.
If these two trends persist and continue to strengthen, the actual runway available for IB and other legacy brokerages is going to be smaller than what appears. There will always be people like us and other RIA's who will continue to trade in individual stocks, options and futures, but it is a decent possibility that this population is slowly shrinking. The counter trend to this is growth in international accounts, but slowly but surely the index fund trend and robo advisor trend will catch up even there.
I agree the competitive landscape here is very much like GIECO's competitive landscape, but the major difference being there is no legislation here forcing people to buy the product like it is in auto insurance. That kind of captive market is worth a lot. IB might still do better compared to other legacy brokerages, but is still susceptible to "Silicon Valley" competition like most legacy business models.
That said I would still buy it @$30 if the market presents me with that opportunity.