Ticker tape, soggy from the damp San Francisco afternoon, matted the gutters of Market Street on Halloween. Countless faces among the thousands of people packing the city center sported fake beards of every make and material—from cardboard to foam, paint to hard plastic. Every storefront, from cafés and department stores to strip clubs and head shops, displayed congratulatory signs bearing some variation of the phrase: San Francisco Giants, World Champions.

For A’s fans, who could be seen in small numbers at the parade, their green hats and jackets standing out in the sea of orange and black, this was not an easy phrase to read.

“Well, we still had a great year anyway,” said A’s fan Gil Hernandez, dejectedly watching the celebrations around him. “And it’s good for the Bay economy when either the Giants or the A’s rock it.”

He made it sound like there’s a lot he was trying not to say. For many A’s fans, seeing the better funded, more widely supported Giants flourish in the national spotlight—for the second time in three years—is a bitter end to what had once been a promising year for the A’s. A late season surge put the Oakland club on the top of its division, but a tough loss to Detroit’s in the first round of the playoffs ended World Series hopes for the A’s.

Hernandez is a dedicated, lifelong A’s fan, raised in the East Bay and living in Hayward, but his son Riley has been swayed by the Giants. “I followed the A’s all season,” said Hernandez with a sigh. “And I would cheer on the Giants with my son.”

Along with Riley, thousands of other children screamed at the sight of their favorite players riding by in convertibles amid the sulfur smell and steady snap of firecrackers, the call-and-answer of vuvuzelas, and the laughter and talk of over a million happy fans in downtown San Francisco.

“The fanbase is ridiculously passionate,” said Scott Rowe, a Canadian tourist visiting San Francisco on Halloween with a group of friends from Toronto. “We were in Napa when they won,” he said. By way of describing the celebration of Giants fans in the North Bay, Rowe shook his head and said, “There was mayhem.” The group had been in Seattle when the series began, and Rowe said Giants fans in Washington “were freaking out.”

And did they hear anything about the A’s while they traveled all along the West Coast?

“No,” said the six of them, looking at each other and shrugging.

The A’s and the Giants have an odd connection at all times, but never more so than in 2012. Two of the Giants’ post-season heroes, Barry Zito and Marco Scutaro, were key players on the A’s 2006 playoff team—products of Oakland’s famous “Moneyball” years. The Detroit Tigers, the team the Giants swept to win the World Series, is the same club that eliminated the A’s.

“Other teams always scoop up our players,” said Hernandez of the ex-A’s now on the Giants roster. “We get gutted.”

But Giants fans’ reaction, by and large, shows a more familial attitude to their cross-bridge neighbors.

“I love that Giants exacted revenge on the Tigers,” said Glen Loutey, a longtime Giants fan from Berkeley. His expression all but said: Nobody picks on my little brother but me. Like many Giants fans, he has a soft spot for the upstart, underdog A’s.

“I’m a defender of Oakland,” Loutey said. “The Giants don’t need defending.”

Loutey’s proof was in the parade turnout. Over one million people flooded into San Francisco from all over the Bay Area on Wednesday—including many from the East Bay, where fans clogged all BART lines into the city to see the Giants’ celebrate.

But according to Chris Dobbins, founder and president of the nonprofit Save Oakland Sports, what most A’s fans don’t realize is that they should all be celebrating. “In a weird, twisted way,” he says, “the Giants winning helps the A’s stay in Oakland.”

Dobbins is one of eight people who serve on the Oakland Coliseum Board of Commissioners , which oversees the operation of the A’s stadium. He says the Giant’s fanbase is growing. Season ticket purchasing increases when a team wins the World Series, he says, as do luxury seat reservations from businesses from all over the Bay Area.

“San Francisco’s the premier city in the Bay Area; Oakland is the second, or stepchild,” says Dobbins. “Not to be overly dramatic. But that’s kind of the idea.”

Never before has this sounded good to A’s fans, but right now it might be—at least for those committed to keeping the A’s in Oakland. For the past few years, A’s owners have been trying to move the team south, to either San Jose or Fremont. As these areas become stronger parts of the Giants’ market, in the wake of the team’s success, they lose some appeal as a new home for the A’s.

While moving the franchise south may never have been the strongest option, given the Giants’ longstanding popularity on the Peninsula, their second championship in three years may have slammed the door for good, Dobbins argues.

“They’ve really solidified that fanbase even more,” he says, which effectively shortens the A’s list of options for a move. At this point, he says, the only way for the A’s to stay profitable sharing the Bay Area is for the team to put down its roots for good in Oakland.

Dobbins’s organization—which works in conjunction with city government to advocate keeping the Raiders, A’s and Warriors in Oakland—is active in building these roots. On Halloween, as the Giants parade was winding down and fans were heading home, Dobbins was working with other members of Save Oakland Sports to set up a Berkeley haunted house with UC’s Theta Delta Chi fraternity. This was the sixth year he’d run this fundraiser, which helps raise money for The Green Stampede, another nonprofit started by Dobbins that for the last twelve years has provided tutoring, mentorship and A’s tickets for underprivileged students in East Oakland.

On Wednesday night, many scary-masked Green Stampede tutors were jumping out at college students from behind corners. These members of the A’s fanbase spend their summers helping local students with homework afterschool, and they spent Halloween dressed as mad surgeons, chainsaw killers and demented clowns.

“Lots of season ticket holders are helping out too,” Dobbins said. The Green Stampede is one of many community groups, he said, that are able to leverage the A’s community and A’s fandom to into civic volunteering.

But even amidst the screams of happily tormented college kids in the haunted house, the A’s fans among the organizers had dampened spirits. Far from thinking about the long-term impact of this season on their team, they felt the sting of the Giants’ celebration. “It’s freakin’ weird, man,” said Victor Morales, Oakland resident and longtime A’s fan.

He said he doesn’t look forward to having to live across the bay from the smug World Champions again. On Halloween, Morales dutifully wore his A’s gear, knowing it was parade-day across the water—a team hat, and a Dia de los Muertos-themed skull tee shirt in A’s colors.

“I don’t root for the Giants to do bad,” said Morales’ friend and fellow A’s fan Martin Leon. “I just want the A’s to be better.”

Keith Salminen, an A’s fan who hosts an internet talk show called “A’s Fan Radio,” said he sees the same boon as Dobbins in the expansion of the Giants fanbase. On a break between bouts of yelling crazed drill-sergeant-commands at haunted house victims, he shouldered the fake rifle that matched his army fatigues and shrugged off his discomfort with the Giants’ victory. “It puts pressure on the owner of the A’s to commit to Oakland,” he said, “or sell to someone who will.”

It’s a tough idea to grasp right now, says Dobbins, but that’s how A’s fans have to think about it. He doesn’t expect most fans to be able to reconcile this ambivalence so soon after watching the Giants win. “We’re jealous,” he says.

But somehow, even though the World Series trophy ended up on the wrong side of the bay, he says, “This was a great season for the A’s.”