Before investing, one of the first questions we ask any potential portfolio company is "Who are your natural predators?" In our case, we're looking at regulatory threats and the answer has historically been the entrenched interest in whatever industry they're disrupting.

Taxi medallion owners for Uber, hotels for Airbnb or casinos for FanDuel, and so on.

But over the last twelve months, two new trends have emerged, both with real implications for startups and their investors.

Who comes next?

The first trend is what happens when you've actually killed the entrenched interest. A recent story in the New York Times began, for the first time, to talk about the yellow cab sector in New York City as an anachronism (replete with quotes from old guys proclaiming that traditional taxis aren't dead yet, which is like a baseball owner saying he has confidence in his manager).

If yellow cabs are no longer seen as real competition for Uber in some markets, then the question becomes: who's coming at them next?

It could be rental car companies, petrified that they're next (they are). It could be the Teamsters worried about autonomous trucking (Uber owns Otto, the leading autonomous trucking startup). It could be older delivery services like Seamless worried about UberEATS.

On one hand, vanquishing the enemy is key and Uber's consistently doing just that. On the other hand, unless you just stop innovating altogether, new enemies will regularly emerge - and not knowing who's coming at you next can often be even more difficult than fighting the enemy you already know.

Startups disrupting startups

The second trend occurs when your battles with the usual suspects create a weakness that new startups can exploit.

Take Airbnb. The company is still enmeshed in (often losing) battles with the hotel industry, affordable housing advocates and hotel workers unions all over the word. Those battles are creating so much political damage, such stark divides and so many openings that new hotel/ home sharing startups can find markets and opportunities just by exploiting Airbnb's problems.

Enter Sonder. From what we've seen, Sonder offers short term rentals - like Airbnb - but they lease the properties first so they're the rentor every time. New York's recently enacted law prohibiting short term Airbnb rentals would presumably block Sonder too.

But Sonder's control over the supply chain means it can use Airbnb's problems to not only draw clear distinctions, but to cut deals that allow them to operate in ways Airbnb cannot (individual homes listed on Airbnb from time to time, for example, can't be union shops but entire, dedicated properties controlled by Sonder could be).

That creates real opportunity. Startups disrupting startups through regulatory arbitrage is a new frontier that will emerge across multiple industries, creating opportunities for multiple early stage startups and headaches for multiple growth stage startups.

The playing field on the startup political front has clearly changed. It's no longer just startup vs. entrenched interest. It's old startup vs new startup. It's older startups vs versions 2.0 and 3.0 of entrenched interests. In some cases, it will even be startups vs antitrust regulators.

How each startup understands, preempts and handles each new type of threat will sometimes be the difference between success and failure of their entire business.

Only the savvy will survive.