When health care firms that haven’t been around very long announce new venture-capital financing, it’s hard to miss the big numbers.

This year, $225 million went into an East Coast health insurance firm called Oscar and an additional half a billion dollars of equity was just raised by Bright Health of Minneapolis.

These firms are very much still startups, and you can hear a little Silicon Valley-style language in how they talk about themselves.

Oscar claims to make health insurance simpler and easier to understand, yet it describes itself as “the first direct-to-consumer health insurer, pairing member engagement with our own full-stack technology.”

Well, that does sound better than having half-stack technology.

But the bigger point is how it’s at least a little surprising that upstarts can raise so much capital to jump into an industry with so many barriers to entry.

Health care is highly regulated, both nationally and state-by-state, and relies on a hopelessly complex payment system the incumbents have all mastered.

Scale matters, too, including the benefits of operating with a brand people respect when the stakes — health care and what it costs — are so high.

Yet entrepreneur and venture capitalist Tony Miller said it’s a much different world in venture finance than it was 10 years ago.

And the first half of the year “produced the largest two-quarter investment period ever for venture-backed health care companies,” according to Silicon Valley Bank.

To illustrate his point, Miller talked about the 2013 zombie apocalypse film “World War Z,” starring Brad Pitt, where the Israelis somehow anticipated the zombies would come and built a wall to keep them out.

The problem of relying on a wall, though, is once the wall is scaled or breached the zombies run wild.

The health care system seems similarly walled off,