The passing of the cyclical peak in the Australian mortgage market in mid 2007 (with monthly finance commitments of more than $22 billion on a trend basis) is proving testing for plenty of business models in the sector.One provider apparently unfazed about the turn in the market, and the impact of rising interest rates at this stage in the cycle, is a relatively fresh mortgage aggregator, X Inc.In October 2007 X Inc Finance merged with Ray White Group's Electronic Mortgage Organisation Channels of Australasia Pty Ltd, (eMOCA), comprising Ray White Financial Services, Loan Market and REA Home Loans.The merged entity  had a loan book around $10 billion. Chief executive Jennifer Nielsen at the time announced an ambitious target of a $30 billion book by 2010. (In the niche that is mortgage aggregators, book size refers to the aggregate level of home loans brokered by the firm's network and on which the aggregator and brokers share commission income). Nielsen is still pursuing that target.Nielsen said of the target: "That view (projection) is based on a discounted version of our performance over the last three and seven years, effectively," and even with Australian mortgage system growth seemingly over, for now, Nielsen still views the target as achievable.To reach the target, X Inc is in a broker recruitment drive adding around 40 brokers in the last three months, bringing the total close to 540."We are on target for recruitment, and those who come to any of the brands are coming for the number one sales positioning, which is that we are a branded aggregator, and the people who come to us have an interest in that."For December 2007 Nielsen said X Inc experienced its busiest enquiry December on record, as borrowers explored different interest rate options in a rising market.One twist is that in January borrowers asking about refinancing exceeded new borrowers by five to one."We had a slower October than expected, due to borrowers putting off the decision until after the election," she said.Nielsen added that business levels so far in January are strong and ahead of the previous year's corresponding  enquiry levels.This is in contrast to early trends at Australian Finance Group (the largest aggregator). AFG's general manager of sales and operations, Mark Hewitt, said last week that "January has taken longer for things to get up and running (this year). Normally by the ninth January you would expect business to be up and running, but it is still relatively quiet."Hewitt added that the current market conditions starting a new year are the most turbulent in recent history due to the uncertainty of global funding markets and the big banks' increasing variable rates over official movements."I think we will see refinancing increase as we see borrowers look for other alternatives. We expect a percentage increase in customers refinancing compared to new borrowers."AFG's December 2007 index (which measures its own sales, and published a week ago) shows loan to valuation ratios falling to their lowest level since the index's inception three years