In May 2005, the airline's holding company, Allegiant Travel, completed a private equity placement worth $39.5 million that was funded by the investment firms of ComVest and Irelandia II. In November 2006, Allegiant filed a registration statement with the Securities and Exchange Commission in anticipation of a planned initial public offering of its Common Stock. It raised $94.5 million in equity capital with 5.75 million shares worth $18 each. It began trading on the NASDAQ Stock Market under the ticker symbol "ALGT" in December 2006.
In May 2015, Indigo and Frontier announced the departure of David Siegel as CEO. He had already previously turned over the role of president to Barry Biffle, formerly of Spirit Airlines. Siegel was not immediately replaced. Instead, his duties were split between Biffle and Indigo chairman Bill Franke. Biffle cited operational issues in connection with Siegel's departure.
In April 2010, Allegiant purchased six Boeing 757-200 aircraft from Thomson Airways for flights to Hawaii with the delivery of the first two in the following months. In September 2011, Allegiant Air introduced the 757 into service from their main hub in Las Vegas. Allegiant later began using the ETOPS configured 757s for service to Hawaii. Fresno and Las Vegas were the inaugural destinations with nonstop service to Honolulu, Hawaii. Nonstop service to Honolulu was then added from Bellingham, Boise, Eugene, Phoenix (via Mesa Gateway Airport), Santa Maria, Spokane and Stockton. Nonstop service to Hawaii was also planned from Monterey, CA but was not actually operated. Allegiant then began to reduce its Hawaii service after determining that the extensive and costly maintenance check - which happens about every six years and costs upwards of $1 million - would not be efficient on the aircraft they flew to Hawaii.
On August 4, 2008, the Associated Press reported that jetBlue would replace their recycled pillows and blankets with an "eco-friendly" pillow and blanket package that passengers would have to purchase for use. Each package will cost $7 and will include a $5 coupon from retailer Bed, Bath and Beyond. This decision is the latest in a series of moves designed to increase revenue. jetBlue told the Associated Press that it expects to collect $40 million from passengers selecting seats with extra legroom and $20 million from passengers paying $15 to check a second bag. As of September 8, 2008 JetBlue charges passengers $10–30 for an extended-leg-room seat depending on the length of the flight.
The bankruptcy allowed Maurice J. Gallagher Jr., one of the airline's major creditors, to gain control of the business. A veteran leader of low-cost airlines, Gallagher had worked with WestAir and as CEO of ValuJet Airlines. In June 2001, Gallagher restructured Allegiant to a low-cost model, focusing on smaller markets that larger airlines did not serve with mainline aircraft. Allegiant's headquarters and operations were also moved to Las Vegas.
The flight personnel and cabin crew where not friendly at all and continuously knocked my shoulders (which where wider than the sear backs) every time they came by and hit my right leg which I had placed on the outside of the seat in front of me as I had a brace on that leg and did say excuse me or I’m sorry the whole time that they hit my leg or my shoulder. By the way and I didn’t tell them but I have undergone reverse shoulder surgery on both of my shoulders/arms and I really don’t expect to get hit every time they pass me
In February 2012, Frontier Airlines cut five nonstop routes from Milwaukee. This move "reduced Frontier's daily departing flights out of Mitchell International from 32 to 18," or 56%. Frontier announced further layoffs in conjunction with this route change: up to 446 Milwaukee-area employees were affected by the job cuts that occurred between April 15 and April 30, 2012.
On July 1, 2010 Allegiant returned to Long Beach Airport (LGB) in Long Beach, California having previously served LGB with DC-9 jets with nonstop flights to Las Vegas (LAS) and Lake Tahoe (TVL) in 2000. The airline also intended to fly from Bellingham International Airport and Stockton several times a week; however, there is no service at present flown between these two cities although Allegiant continues to serve Stockton with flights to Las Vegas, Phoenix/Mesa and San Diego. In November 2011, Allegiant closed its Long Beach facility and consolidated all Los Angeles area flights at Los Angeles International (LAX).