For shits and giggles, if someone good at math would like to do an analysis to find the most efficient determination of how many Darkcoin would have to be sold and how many Spreadcoin would have to be bought (with the total BTC that would have to be spent for them) for SPR to pass Darkcoin in price, in a manner that at least makes sense as I understand there are many variables, I'll pay you 400 SPR.
For example, if there is a 1000 DRK buy wall then selling into that isn't going to be efficient. So 0 DRK would need to be sold but XXX,XXX SPR would have to be bought.
Or the most efficient means to do it would be to sell 23,450 DRK and buy 114,500 SPR because of current and anticipated buy and sell walls.
Not easy math I understand. It's far beyond my capabilities.
This isn't really possible to answer, as it depends on liquidity, which is largely unknown (at least the way I see it). You can't "anticipate" buy and sell walls with any sort of confidence.
On the other hand, if you're just talking about absolute price in BTC, one could simply take a look at the current order books and come up with some numbers pretty quickly, noting of course that the result would be a temporary equilibrium in price. A few seconds/minutes later the market would have shrugged off your buys/sells to some extent.
Want to ensure SPR's price attains and stays above DRK's? (~0.00785) Put in an order for every SPR in existence at 0.00786; ~1,760,000 * 0.00786 = 13,833.6 BTC. Note of course in reality it will take much, much less than that at least for the near future (until significantly more are mined). I'd estimate 1/10th to 1/5th of that amount, but that's not really grounded in anything. With the buy walls existing in DRK at the moment, selling is probably not going to be very productive to this hypothetical.
Edit: Bittrex's current order book says it'd require 148.9120 BTC to achieve > 0.007 (order book gets really thin up there). Selling DRK is less efficient than clearing out the last few rows in the SPR order book. Note of course that buying this way wouldn't last more than a few seconds at most.