Weekly Waiver Wire Roundup — May 4, 2026

Carlos Cortes posted an absurd .831 wOBA with a 102.5 mph average exit velocity over the past seven days, and he's still sitting at just 24% ownership — that's the kind of inefficiency that wins waiver weeks. Across the board, 80 rising signals fired this week, with a heavy concentration in relief pitching, outfield bats, and catching — positions where the wire is actively reshuffling. Here's everything you need to act on before Tuesday's waivers process.

Top 5 Adds of the Week

Miguel Vargas (1B/3B, CWS) — 56% Owned (+32%)

Vargas is the top add of the week and it isn't particularly close from a process standpoint. His 7-day wOBA of .472 represents a massive surge over his .352 trailing 30-day mark, and the underlying plate discipline supports the breakout: a 21.2% walk rate over the past week (up from 16.0% over 30 days) paired with a 93.3 mph average exit velocity and 50.0% hard-hit rate. He slashed .308 with 3 home runs across 33 plate appearances — a genuinely solid sample. Ownership has already surged 32 points, so the window is closing fast in competitive leagues. If he's somehow still available, he's the priority claim.

Davis Martin (SP, CWS) — 50% Owned (+27%)

Martin's 7-day strikeout rate of 28.0% (up from 22.9% over 30 days) is elite-tier, and a 1.27 FIP across 12.0 innings pitched confirms the dominance isn't a mirage of sequencing luck. His ERA sat at 1.50 with 10.5 K/9 for the week. The workload signal — two starts, 12.0 innings — suggests the White Sox are giving him a full rotation leash. Ownership jumped 27 points this week and should continue climbing. He's a must-add in all formats.

Josh Jung (3B, TEX) — 43% Owned (+27%)

Jung's week was a masterclass in contact quality: a .514 wOBA, 95.0 mph exit velocity, 52.1% hard-hit rate, and a strikeout rate that dropped from 15.6% to just 10.7%. He hit .375 with 2 homers across 28 plate appearances, and the walk rate ticked up to 10.7% as well. The Rangers' third baseman has always had the raw talent — this looks like the fully healthy version putting it all together. At 43% ownership, he's still available in a surprising number of leagues.

Carlos Cortes (OF, ATH) — 24% Owned (+22%)

The numbers here are almost hard to believe: a .831 wOBA, .692 batting average, 102.5 mph average exit velocity, and a 100.0% hard-hit rate on batted balls. Cortes added 2 home runs and a 12.5% walk rate that climbed from his 30-day mark of 10.1%. Yes, this is a small-sample heater, but the exit velocity data is real and the quality of contact is legitimate. At just 24% ownership despite a 22-point surge, he remains widely available. The batting average will regress, but the power indicators suggest the production has staying power beyond this week.

Moisés Ballesteros (C, CHC) — 29% Owned (+13%)

Catching is a wasteland, which makes Ballesteros all the more valuable. His 7-day line — .333 AVG, 2 HR, .488 wOBA — is backed by a 72.2% hard-hit rate and 93.4 mph exit velocity, with his strikeout rate dropping to just 8.7% (down from 12.7% over 30 days). He logged 23 plate appearances in the past week, confirming consistent playing time. For a position where finding a reliable bat is nearly impossible, Ballesteros is delivering impact production at a 29% ownership rate. He's a top-priority catcher add.

Biggest Risers in Ownership

Miguel Vargas (+32%) leads all ownership gainers and rightfully so. The combination of a .472 wOBA, 21.2% walk rate, and multi-positional eligibility makes him a fantasy asset at scale. The data fully supports the hype.

Davis Martin (+27%) and Josh Jung (+27%) are tied for the second-largest ownership jumps. Martin's 1.27 FIP across 12 innings is as clean a pitching signal as you'll see, while Jung's .514 wOBA and 95.0 mph EV with a declining K-rate make him one of the most complete hitters on the wire right now. Both pickups are justified.

Carlos Cortes (+22%) is the one with the most remaining upside in ownership growth — still under 25%. His 102.5 mph exit velocity is the kind of number that demands attention. Moisés Ballesteros (+13%) rounds out the top five risers. Given the positional scarcity at catcher, expect his ownership to keep climbing through the week.

Buy Low Candidates

This is where the real edge lives. These players have strong underlying metrics but haven't seen meaningful ownership movement yet. The market is sleeping.

Spencer Steer (1B/OF, CIN) — 13% Owned

Steer's 7-day profile is stunning: an 83.3% hard-hit rate, 95.5 mph exit velocity, .425 wOBA, and a strikeout rate that cratered from 23.7% to just 9.1%. The walk rate spiked to 18.2%. He hit .294 with a homer across 22 plate appearances. At 13% ownership with virtually no movement (+1%), this is one of the most glaring inefficiencies on the wire. Multi-positional eligibility adds roster flexibility.

Nathan Church (OF, STL) — 4% Owned

Church's .581 wOBA and 4 home runs in the past week jumped off the page. His strikeout rate dropped from 24.3% to 9.5%, exit velocity sat at 94.8 mph with a 57.5% hard-hit rate, and he posted consistent playing time with 21 plate appearances. At 4% ownership, essentially nobody owns him. This is the profile that could become next week's top add.

Coby Mayo (1B/3B, BAL) — 3% Owned

Mayo went on a tear: .541 wOBA, 3 homers, 102.6 mph exit velocity, and a 66.7% hard-hit rate. His strikeout rate improved from 27.0% to 20.0%. The raw power has always been there with Mayo, and at 3% ownership, the cost to acquire him is essentially nothing. The Orioles' lineup provides ample run-scoring opportunity around him.

Ty France (1B, SD) — 0% Owned

A .681 wOBA at 0% ownership. France hit .400 with 2 homers, a 97.3 mph exit velocity, 72.2% hard-hit rate, and a 0.0% strikeout rate across his plate appearances. This is an early-signal sample, but the Statcast data is too loud to ignore at the cost of a free roster spot.

Luis Campusano (C, SD) — 1% Owned

Another catcher option for those who missed Ballesteros. Campusano's .717 wOBA is backed by a 100.0% hard-hit rate, 102.7 mph exit velocity, and 2 home runs while hitting .500 on the week. It's an early signal, but the exit velocity quality is the real deal. Essentially free in all formats.

Brandon Marsh (OF, PHI) — 11% Owned

Marsh posted a .452 wOBA with a 75.0% hard-hit rate, 97.1 mph exit velocity, and a strikeout rate that dropped from 20.7% to 12.5%. He hit .391 with 2 home runs across 24 plate appearances. Consistent playing time in a potent Phillies lineup makes this a high-upside stash. At 11%, the market hasn't caught up.

Mark Vientos (1B/3B, NYM) — 6% Owned

Vientos' wOBA surged from .276 to .491 in a week, with 2 home runs and a walk rate that jumped from 5.2% to 12.5%. His 94.5 mph exit velocity and 58.3% hard-hit rate support real power production. At 6% ownership with zero movement, the market is ignoring a player with significant power upside in a favorable lineup.

Edouard Julien (1B/2B, COL) — 3% Owned

Julien's .455 wOBA comes with a 97.7 mph exit velocity and a 14.3% walk rate. He hit .353 with a homer across 21 plate appearances, showing consistent playing time. The Coors Field home park adds another layer of upside. At 3% ownership, he's a high-ceiling stash at a thin middle-infield position.

Nathaniel Lowe (1B, CIN) — 1% Owned

Lowe quietly slugged 4 home runs in the past seven days with a .532 wOBA and an improved strikeout rate (11.1% vs. 16.7%). The 90.8 mph exit velocity is modest, suggesting some sequencing fortune, but the power output at 1% ownership makes him worth a speculative pickup.

Marcelo Mayer (2B/3B, BOS) — 6% Owned

Mayer's .421 batting average and .423 wOBA came with a remarkable 0.0% strikeout rate across 20 plate appearances. His exit velocity of 84.8 mph and 44.4% hard-hit rate suggest the contact quality isn't elite, but zero strikeouts in a week of regular playing time from a premium prospect in Boston's lineup is a signal worth monitoring.

Carson Benge (LF, NYM) — 10% Owned

Benge's ownership actually dipped 2% this week despite a ridiculous .478 wOBA, .438 batting average, and a strikeout rate that fell from 18.2% to just 6.2%. His 95.8 mph exit velocity and 60.0% hard-hit rate confirm the contact quality. The cooling ownership trend makes him a contrarian buy-low in deeper leagues.

Colt Keith (1B/2B/3B, DET) — 19% Owned

Keith's ownership dropped 6 points despite his wOBA climbing from .305 to .373, his batting average sitting at .400, and his strikeout rate declining from 21.3% to 18.8%. The 94.0 mph exit velocity and 50.0% hard-hit rate are solid. Managers appear to be bailing just as the underlying numbers are improving — a textbook buy-low window.

Position Scarcity Report

Relief Pitching (RP): The most active signal group this week with 19 RP signals, reflecting the volatility inherent to bullpen roles. Key names to monitor include Devin Williams, Tanner Scott, Andrés Muñoz, Mason Miller, and Ryan Helsley. Closer roles continue to churn — stay active on the wire if saves are a category need.

Outfield (OF): Nine outfield signals fired this week, led by Cortes, along with watch-list names like Brandon Marsh, TJ Friedl, and Church. The position is deep enough that quality is still available, but the elite options are getting claimed quickly.

Catcher (C): Eight catcher signals is an unusually high number for the shallowest position in fantasy. Moisés Ballesteros leads the group, but Luis Campusano, Travis d'Arnaud, Henry Davis, Miguel Amaya, Mitch Garver, and Danny Jansen all showed improving metrics. If you're streaming catchers, this is a rare week with options.

Starting Pitching (SP): Only four pure SP signals beyond Martin, including Chase Burns, Jacob deGrom, Mitch Keller, and Rhett Lowder. Add in the five SP/RP dual-eligibles and the pitching wire is active but not overflowing. Quality arms remain scarce.

First Base (1B): Five dedicated 1B signals plus multiple multi-position players who qualify there. Christian Walker, Matt Olson, and Yandy Díaz all appeared in the signal data. The position is relatively deep this week.

Middle Infield (2B/SS): Thinner than expected. Alex Freeland, Hao-Yu Lee, Marcelo Mayer, and Joey Ortiz offer varying degrees of upside, but none have broken through in ownership. Multi-position eligibles like Edouard Julien and Colt Keith help fill the gap.

Looking Ahead

The biggest storyline entering Week 5 will be whether the White Sox duo of Miguel Vargas and Davis Martin can sustain their breakouts as ownership approaches mainstream levels. Watch Nathan Church and Coby Mayo closely — both profiles (.581 and .541 wOBA respectively, with elite exit velocities and near-zero ownership) look like prime candidates for next week's top-5 adds if the production continues. The relief pitching carousel showed no signs of slowing down with 19 signals, so expect continued volatility in closer roles — keep your FAAB reserves flexible and prioritize saves sources that come with strikeout upside like Andrés Muñoz and Mason Miller.