When Slack goes public, it's poised be another home run for VC firm Accel as it continues a big winning streak

With Slack getting ready to go public this week, venture firm Accel is poised to rack up another big win.

2019 is proving to be a banner year for Accel, as its portfolio companies either go public or get acquired for big bucks.

Accel is a classic, top-tier venture capitalist with a long history in Silicon Valley.

Its ongoing success gives pause to this idea that the venture capital model is really being blown up, as is the trendy talk these days.

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2019 is producing one blockbuster IPO after another, and next up is Slack, which is expected to go public on Thursday.

Except that Slack isn't technically having an IPO, because it is having a more unusual direct listing. That means it's going public without an underwriter, which is to say, without a banker buying shares and helping to sell them to institutional investors.

Slack is simply going to allow the shares that people already own to be sold to public investors. The company also isn't selling any new shares to raise money. There will be no lock-up period for shareholders, including employees and venture investors. We don't know yet how many shares will be up for sale. Slack hasn't released information yet as to how many of its principal shareholders are selling, or how much.

One notable venture investor in Slack is Accel, which owns 24% of the company.

Accel also hasn't made it clear yet if its going to sell many shares in Slack's listing (and it declined comment when we asked), but it may not have to to see a return — Accel is already having a banner year in terms of its investments.

Read: After selling his company for $6.5 billion and doing 40 angel investments, Ross Mason is joining an unusual quant-like VC firm

In addition to its position in Slack, Accel also held a 12% stake in PagerDuty and 20% of CrowdStrike, and an unknown stake in Fiverr, all which recently went public. Accel was an early investor in Fiverr and bought shares in later rounds, too, but didn't get its stake up above 5%, which is the point at which the size of its holding must be publicly disclosed.

It also had stakes in startups that were bought for big bucks this year, incliding HotelTonight, bought by Airbnb for a reported $465 million, and Demisto, bought by Palo Alto Networks for $560 million.

All told, 18 Accel-backed companies have gone public or been sold so far in 2019.

And this is on top of a pretty good 2018 for Accel, too.

Last year, its portfolio companies that went public included DocuSign, Dropbox, Spotify, and Tenable. And its portfolio companies that were bought for big bucks include Qualtrics, which was sold to SAP for $8 billion. Accel had a 16% stake in Qualtrics and 34% stake in Tenable. Then there was PillPack (bought for $1 billion by Amazon), Flipkart ($16 billion buy by Walmart), and Broadsoft ($1.9 billion by Cisco), according to Pitchbook, the database that tracks such deals.

Still, even with these wins, the Forbes 2019 Midas List pegs Accel as the number-two most-winning VC in Silicon Valley, with six partners making the cut. It was behind Sequoia Capital, the legendary venture firm, which had 10 of its partners make this year's Midas List.

Still, the nature of the VC industry is that success breeds success, as winning deals attract more startups to the table. Given all the talk recently about blowing up the VC model, we're just pointing out that Accel, as classical VC firm founded in 1983, isn't being blown up. It's having a heyday.